How do I open/backup a Quicken QDF file over a LAN?

You should not do the backup while connected or having the file open in another computer. The file should be opened up only on one computer at the time. The backup you can save to the other without problems.
Quicken is not designed to be used in a multiuser environment. You have found a workaround for it by opening it first in one and then the other but it is giving you this problem because the ~ is the naming used by Quicken for temporary files.
You actually should be using Quickbooks which uses the Quickbooks connector and is designed for multiple users.

I wasn't being clear. I never have the file open on more than one computer at a time.

Ok..... You need to search for a file in the C:\Windows directory of each machine and type in manually the proper path for the file. The file name has changed over the years and it's been a long time since I've used Quicken 2006 (I now use the 2010 version) but it is easy to find:
1. Do a search on your C:\Windows for all *.ini . One of the results will be Quicken.ini or some similar name like QW.ini. You will know it is th right file when you double-click and open it and you see inside of it.
2. You should see something like this:
[Quicken]
Version=19,Quicken 2010
Platform=Win32
UsedOnlyForQuickPayroll=1
ExePath=C:\Program Files (x86)\Quicken\QW.EXE
[autopatch]
PatchFatalError=0
testpatch=1

Notice the ExePath on my Windows 7 is  C:\Program Files (x86)\Quicken\QW.EXE
In your scenario you must change it to your actual path:
Computer1:
ExePath: \\Computer2\Program Files\Quicken\QW.Exe (it is not exactly like this - this is just a sample)
On Computer2:
ExePath: C:\Program Files\ Quicken\QW.EXE (again: it is not exactly like this but whatever your real path is)
Remember, I'm using Windows 7 and Quicken 2010 so in Quicken 2006 and XP it might not even be called ExePath. I might just say Path or anything else.
The point here is: look for the *.ini file that configures the location of the Quicken file on each computer and modify the path accordingly for each.

Matters not. As stated above, you need QB with multiuser license installed on each of the pc to do what you want.
You could try and sync the file and make available for each pc using a free option of a program such as Dropbox.
Haven't tried it with QB so not sure how well it would work as QB has many restrictions built in, but give it a try.
Good luck

By the way.... if this works for you and you decide to assign the points to me, please remove the " Databases Miscellaneous" zone and add rather the "Windows XP Operating System" Zone since the 2 machines we are dealing with have XP and the other Windows 7 and the 3rd zone would be "Quicken Financial Software" ..... If you do this for me I would get the points credited appropriately to the correct zones.... I would really appreciate this, but you must do it before assigning the points.

I notice I have two Quicken.INI files. The first file seems to refer to the second. I've not modified either.
C:\WINDOWS\Quicken.ini

[Quicken]
Version=15,Quicken 2006
Platform=Win32
UsedOnlyForQuickPayroll=1
ExePath=C:\Documents and Settings\Mike\Application Data\Intuit\Quicken\Config\QW.EXE
Visioneer=1

C:\Documents and Settings\All Users\Application Data\Intuit\Quicken\Config\Quicken.ini

[Alerts]
DontShowDeleteDlg=
DontShowDeleteAllDlg=
DontShowViewAllDeleteDlg=
[Quicken]
Exepath=C:\PROGRA~1\QUICKEN\QW.EXE
AutoBackup=3
AutoCopy=5
UpgradeSeen=
QCardGroups=
QCardSettings0=
MSMoneyReady=0
sCurrency=$
sDecimal=.
AddApps=;QHI
Billmind=off
Version=15,Quicken 2006 Basic R2
sThousand=,
testpatch=0
Periodic_update_period=0
Periodic_last_update=08/12/2007
Platform=Win32
UniRegEOC=640489
OracleSKU=281875
RecalcMarketValue=0
NewCatPrompt=1
CatReminder=1
UseSemicolon=0
[Portfolio]
Exepath=C:\Program Files\Quicken\ATWORK.DLL
[Reconcile]
Instruct=1
[Internet]
Stay_Connected=
CreditCheckCgi=
RegisterCgi=
HeadlineBaseUrl=
MaxRequests=
CurrencyRateDownload=http://www.intuit.de/currency/data_de.txt
[Business]
CustomerID=
[QPS]
Ask=0
Permission=0
[Menu]

As I mentioned before, you need to modify the path of the file in
C:\WINDOWS\Quicken.ini
Notice that the first one is for Mike. The second file is for All Users.... I assume you are Mike so this is the one you want to set the path on...
 
 

This is the original string from computer #2
ExePath=C:\Documents and Settings\Mike\Application Data\Intuit\Quicken\Config\QW.EXE

This is the original string from computer #1
ExePath=C:\progra~2\Quicken\QW.exe

On computer #2 I've shared-----C:\Documents and Settings\-----and can access it freely from computer #1.

On computer #1 I've tried both
ExePath=\\Dell\C:\Documents and Settings\Mike\Application Data\Intuit\Quicken\Config\QW.EXE
ExePath=\\Dell\Documents and Settings\Mike\Application Data\Intuit\Quicken\Config\QW.EXE
Each time I open Quicken on computer #1 Quicken rewrites the string to the original.

Being clear in this sort of thing can be challenging so allow me to rephrase the problem in the event that it might help...

There is only one user that needs access to Quicken on each of two computers. (That single user could easily be "All Users" if it mattered to the process of getting the thing to work.) The all-important QDF file has to reside on computer #2. Quicken will never be running on both computers at the same time. The operation of Quicken (as apparent to the user) has to be identical (flawless) on both computers. It works flawlessly on computer #2. The Quicken version I have is 2006. I have no need for anything more, don't prefer to stick anymore money into software, and explaining the differences between old and new version to others is a problem. Note that I can open the QDF file on computer #2 with Quicken on computer #1 but others will have difficulty, as it works now, and even I can't get Quicken on computer #1 to correctly name the backup file on computer #2.

Lol...... let me rephrase the problem .... Quicken is not designed for MultiUser use. This means that you are only allowed to have it installed on one computer at the time. We are searching for a workaround but it is very unlikely (even though technically only one user will be using it - so you are not breaking any law) since the programs, as you correctly noted, modifyies the Quicken.ini every time you use the file.
The only workaround that comes to mind would be that you locate the file on a 3rd computer. This approach would make the path identical for both computer1 and computer2 when they need to access the file. For example:
\\computer3\My Documents\Quicken\QW.exe
 

By the way.... just to get the doubt out of your head..... the "All Users" is the template or default settings that windows uses when you create a new user.... it is irrelevant to what we are trying to accomplish here...

If our work-around has been to run the QW.exe on computer #2 from computer #1 then I don't believe that'll work.

What I want is for the QW.exe on computer #1 to use the QDF file on computer #2 (without having to go through a bunch of extra keystrokes) and back it up on computer #2 without corrupting the file name such that QW.exe on computer #2 can't find it. I thought that was what I asked for but, as I said, being clear is tough. Perhaps I'm just not understanding the instructions I'm given...

As another possibility, I'm wasn't familiar with the syncing software. The idea seems appropriate except I don't want any of my data stored online. Is having the online server involved prerequisite?

As a footnote, I have exactly the same problem to solve with Outlook's PST file.

Ok .... this is how I do it:
I have installed and run Quicken on computer1. The Quicken file is also on computer1. The backup is on computer2. No need to install the Quicken software or open the backup from computer2. It is as easy as this.
For Outlook, the process is different. You can put Outlook file wherever you want and just tell Outlook where to find it.
I like to use 3 backup methods:
One is the online backup with Carbonite (this is instantaneous and is encrypted - Not even their techs can read or open your data).... it is awesome..... we install it to all our customers and believe me... when it comes to handling other persons data .... either you are good or you will be sued.
The second is a software called Goodsync from www.goodsync.com. I basically sync (it allows you to schedule and compare during the day any changes from computer1 and computer2) everything under my user profile (I'm using Windows 7 so everything is contained in one place).
The third is I create once a month a complete image of my whole hard drive to a WD Passport external USB drive.
So .... if you want to talk about being obsessive with my data....
 
Bits....

I get the feeling you've not checked  https://www.dropbox.com/

Yes .... I have and I like it. I like (actually love) the sync features.
What I don't like is the price (twice as expensive as Carbonite for only 50GB).
And I don't like the fact that the rate is dependent on the amount of space you use (to give you an idea: I have about 600GB just of Music and about 1.5TB of software) .......

Carbonite has its drawbacks as well .... the price is great (about $5 per month) but it is based on each computer.
The way we work around this is that we install it on a server, so all the users data (My Documents) in the domain point to a "Users" share and inside the "Users" share each user has his own folder (which is totally private even from the administrator (unless he takes ownership of the folder). This "Users" share is the one we sync with Carbonite so we are still working under their license terms of "One Computer".....

Keep in mind that "backup" in my case is Quicken's backup of Quickens QDF file and, although it has to be solved, it's a secondary problem. I still have to be able to run Quicken from either computer and use the common QDF file with no grief.

I've experimented some with the common PST file and it seems like it might work as simple as telling each computer where to find the one file which is how Quicken should work.

My question about the syncing software is, can you avoid involving the online server?

Yes.... with GoodSync you don't do it online..... you sync locally between your different computers.... they have a free trial .... it is limited but you will get the basic idea of how it works.
Again..... for Quicken to work correctly the way you want it, both computers will have to point to the same path (otherwise it will change everytime you open it). You could use a 3rd computer or a NAS drive (network attached storage drive - basically a hard drive plugged into the ethernet cable of your network). Otherwise it will not work. It is not designed for this. What we are doing, although technically legal (since only one user is using it at the same time), could be viewed as illegal (since you are only allowed to install Quicken on one machine)...

Forget to mention, in order for both computers to be able to point to the same path, the QW.exe file has to be OFF computer1 and computer2 or the path will vary.
To keep this simple:
1. Install Quicken on Computer1
2. Install Quicken on Computer2
3. Put your Quicken data file (lets call it  Mikes_Finances 2009.QDF) on Computer3 or NAS drive.
4. Open the  Mikes_Finances 2009.QDF from computer1. Close it. The path will automatically be saved.
5. Open Open the  Mikes_Finances 2009.QDF from computer2. Close it. The path will automatically be saved.
Now it should always work. Just remember: Never open it from both computers simultaneously.
That's it.......
For the backup: Do the backup to any of the computers.

Correction to above: disregard the first 2 lines....... it is not the QW.exe the one that has to be off ..... it is the Mikes_Finances 2009.QDF the one that has to be off.

Ok, that's a different picture. I was under the impression of just a quicken file being backed up.
With that much backup, online backup becomes prohibitive.
I'm sure a server must have come up in the above comments.
Let me just say that in this picture, i would keep backups local using a server or such with online backup only of more sensitive files and spring for a multiuser licence of QB.
They're not that expensive in the secondary market and nothing gets hacked if one needs to retrace steps especially for valuable data. In the long run keeping it simple is a better option IMHO.

Yes centerv.... I agree. This is what I have been pointing out from the begining: Use Quickbooks.
For only 2 or 3 computers a server would be "Overkill" but it would be nice though.
What we are looking for is for a workaround for an old version (2006) of Quicken so either tool_man or his assistant or partner can input data into Quicken from 2 different computers but with only one user logged in at the time (this is my understanding of what he wants to do).
I am guessing that while he is busy doing something else, he does not want to have to walk away from his computer so someone else can input data into Quicken and viceversa.
Hopefully my last comment will allow him to do this without actually "hacking" or breaking the license agreement with Quicken (since 2 users are NOT using the program simultaneously)...

"4. Open the  Mikes_Finances 2009.QDF from computer1. Close it. The path will automatically be saved."

I experimented by repeatedly opening and closing Quicken on computer #1 having the QDF file on computer #2. It won't remember the path. It always opens with the "Select your data file. What do you want to do?" window. I can cancel that and go to File>recent list and click from that list and the file will open every time but this is the very thing I don't want to have to mess with. I take this as an indication that the notion of involving a third computer won't work. If Quicken won't remember that the QDF file is on computer #2, it won't remember that it's on computer #3.

As a secondary problem Quicken on computer #1 wants to rename its backup file on computer #2 using the ~ which causes Quicken on computer #2 not to be able to find the file.

Since Quicken will never be open at the same time on both computers, I think that GoodSync might work if I can create a batch file that does a two-way sync of the QDF file and the backup file and then opens Quicken. Can I do that with Windows 7 on computer #1 as well as with XP Pro on computer #2?

Actually..... a simpler method has just occurred to me: Why don't you place the main (production file) QDF file on a flash drive and save the backups locally?
This way you don't need a 3rd computer and you would only need to move the flash drive to computer1 or computer2 and at the same time each computer would have a backup copy on it.

>>>>>(to give you an idea: I have about 600GB just of Music and about 1.5TB of software) .......

With that much data to backup, a WHS is not out of the question and to me the most logical.
Changing the ini file etc is a simple way of hacking, nothing to do with license.

The gurus at Intuit have put a lot of time into preventing scenarios such as this from working and from
my end I've not found a satisfactory way to make it happen how you want it.

centerv: at my house, I have 3 servers in the garage on a rack, 8 computers around the house (one in every room, kitchen, living room, family room and den (My Home Office) ...
I was talking about Mike's situation where he only has 2 computers and a 2006 Quicken file, in this situation a Server is overkill unless you are a tech and use it for testing...

Bits
I'm not losing my mind quite yet, although some may disagree with me :-)
The quote above is from the author, earlier.
LMAO
I wont get into the hardware floating around my house. Makes me wonder at times.
In any event, if this isn't solved by tomorrow, I'll have to wait a few days to see the outcome.

LOL .... you are losing it today... this question has just become to long.... I posted that in CommnentId:26135618.

Oh wow.
I'll never be able to explain my way out of this one!
Where's the wet noodle....
ROTF...

That being the case, I'm back to my suggestion of dropbox or multiuser.

But, to add to the confusion, Intuit has an app that for 3.95 a month, at least that was the price last time
I set up somebody with it, that will allow you access to QB (only know it works with QB pro, as that's the only one I've ever used it with) on another pc over the net. The only problem, which I never did research as it was not an issue at that time, was that the QB needed to be open on the remote computer as the applet would not let you open the program otherwise.
Also, for a few dollars more you get to backup and use the QB data file over the net but then the free dropbox is easier.
Don't remember the names but should be easy find on QB site. My head is spinning too much right now.
Cheers and Happy New Year

There was a great deal of effort put forth in trying to understand the peculiar nature of just what it was that was needed. In the end it was the extended discussion that led to a simple solution.

Mapping the drive on computer #2 to computer #1 made everything work.