vista intermittent network connect issue

I am wired to a D-Link DI-624 router.
I have all new cat 5 cables to the PCs except the WAN cable which is cat 5e and is not new.  
I will change the WAN cable to see if it resolves the issue.
I am connecting from internet to modem to router to laptop.
Thanks. I'll try the suggestion brought about by your questions.

Is this the only PC on the network?
Is this a home network?
when you lose your connection, what lights are lit up on your modem?

check for new NIC drivers from your laptop manufacturer if using built in lan port.
check for firmware updates for the router here http://support.dlink.com/products/revision.asp

2 PCs on the network currently, VISTA Home and XP Pro.
SBS 2003, VISTA Ultimate, a wireless Server 2003 r2 and 2 other boxes are slated to be installed for learning and test purposes.
This is a small business network (SOHO).
RE: Modem - I did not notice as modem is across the room.
I will check the NIC driver but laptop is 3 months old.
Will first check for firmware updates to the router for VISTA support.

http://support.dlink.com/products/view.asp?productid=DI%2D624%5FrevC
DI-624 Router does NOT support VISTA 32 per the URL above.
It looks like I must update my router to one that is VISTA compatible.
That is likely the reason for the intermittent connectivity.
Since "Sappbrosts" directed me to the suspected solution, I suggest that you submit a suggestion for me to either to upgrade my router to one that is VISTA compatible or direct connect my laptop to the modem.
I'll then check out the possible solution and if proven to be the actual solution, I'll award points.
Thanks.

I ran Vista 32 just fine with a linksys 54g and a belkin wireless N.  Linksys is by far my favorite brand of router, I usually replace their firmware with dd-wrt firmware so I can amplify my wireless signal.

I wouldnt go for one of those new linksys routers, the ones with the internal antennaes.

We use these at all of our truckstop locations and many of the truck drivers use Vista while connecting to these routers with no problems.

http://www.newegg.com/Product/Product.aspx?Item=N82E16833124190
the wrt54gl will allow you to run linux based firmware if you want, or keep the standard linksys firmware, either way...

And this one is compatible with Vista as stated on the linksys website
http://www.linksysbycisco.com/US/en/products/WRT54GL

I just found a related post as follows, on the Microsoft site.  I, however, realize that I must update my router for VISTA support but the following post indicates that the problem is not due to the router.
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http://social.technet.microsoft.com/Forums/en-US/itprovistanetworking/thread/931468fa-697f-4116-8384-de257f772541/
"Intermittent network connection drops (Vista Ultimate SP1) Pentazer Monday, April 28, 2008 4:07:02 AM 0 votesVote As Helpful "
 
"Hello
I am a technition at an office supplies store and have had a number of computers come in with similar issues to the one I am having. This is becoming so common I decided to post about this issue on the forum.
 
my network connection is intermittently dropping entierly. It can only be restablished if I:
-reset my router for factory defaults (massive pain as I use a static IP for specific ports to be forwarded).
-disable my connection, restart machine, enable connection.
-reset my static IP and reset my router to factory defaults.
-release/renew my router IP then reset my computer.
 
I should note that every time this problem happens which is a few times a month, all my other computers which includes 3 win XP machines and 1 CentOS 5 Linux Server all retain their connections and do not experience any network issues. all my machines are going through the same router, a linksys WRT350n gigabit w/storage link.
 
I have gone through 3 WRT54G and a wired BFSR41v3 (if thats the right model) before using the WRT350N, this same issue has been experienced on just this vista computer on all routers. By all this I conclude the issue is not with the router for the following reasons:
-network connectivity is retained on all other machines.
-it does not matter which router is being used, this issue will happen regardless.
 
I am using IPv4 since nothing seems to support v6 at an internal IP of 192.168.1.75 because I have about a dozen items that need to be forwarded to various internal IPs. This happens on either of my 2 wiered or my wireless connections which are all onboard on my MOBO. I only keep one connection active at any time and only use one network cable, if I need to switch ports I do so physically then enable the new one, disable the others.
 
Troubleshooting:
-I have uninstalled and reinstalled my wiered and wireless network drives.
-I have updated all my network drivers to the most current versions.
-I have reset all settings for all network related devices on my machine and the router.
-I have set the settings back to using static IP and DNS.
___DNS is set to the routers IP 192.168.1.1
___secondary DNS is set to the routers active DNS (I do not remember it off hand).
-I have tested all different routers and even gone direct wired.
-I do not use ANY firewall software of AV software, they only get in my way.
 
keep in mind the network issue only seems to affect the vista machine only.
Due to the fact the divers have been downgraded, upgraded and restored via the vista driver disk that came with the MOBO this cannot be a hardware issue, the hardware is functioning as at times Ive been connected for 2 or 3 months without an issue, then the issue returns. Additionally I can always access the router, I have total internal network connectivity and can connect to other computers too, just nothing outside the internal network.
 
I have discussed this at length with customers and cooworkers who have all, after investigation, experience the -exact- same symptoms I am experiencing on my computer when this is happening. I have exhausted all the solutions I can think of, also the fact that a number of others are reporting identical issues. Therefore I can only conclude the problem appears to be with how Vista handles networks internally.
 
Please, I need a solution to this issue, its driving me out of my mind.
Thanks.
 
 
-EDIT
I forgot to mention that I also upgraded the WRT350n firmware, no change, then factory reset firmware to default, again no change to the solution. Reply Quote"

 The above is from URL: http://social.technet.microsoft.com/Forums/en-US/itprovistanetworking/thread/931468fa-697f-4116-8384-de257f772541/
Therefore,  I do not think that I can justify upgrading the router to Linksys WRT54GL at this time as router changes (WRT54G)  did NOT fix the issue for the above quoted person.
I will swap the WAN cat 5e as suggested and advise.
 

I found an additional Post that indicates problem is NOT with the router but the problem may be the OS.
It is:
"Tuesday, March 17, 2009 6:05:23 AM 0 votesVote As Helpful Brand new HP wx4600 Workstation; came with Vista Business Downgrade to XP Pro; thought it was about time to give Vista a try and reverted system back to Vista Business; same problem as described with losing Internet connection, several times an hour; tried all the fixes above, but none resolved the problem; I see why HP sells the Workstations Downgraded to XP Pro and went back to that; probably won't visit Vista for another year! "

The frequency of dropping the internet connection (as in the prior post) is similar to my issue.  

I do not know if the following will shed any light on the resolution, but the greater frequency of the connection dropping (from the VISTA PC) happens between 6am and 10am.
 
The connection hardly ever drops in the late morning, afternoon and evening.
Could this be related to IPv6 and IPv4 and my ISP and VISTA network code interaction?
What operations / functions take place within the ISP's network and in the internet as far as the DNS and IPv4 and IPv6 transition operations around the world take place?
Could the code that is in VISTA SP1 and and the interaction of code during the transitioning of countries or regions to a didactic IPv4 / IPv6 messaging capability be the source of the problem?
See www.ICANN.org

I just learned from the D-Link support page at http://www.dlink.com/products/vista-support/ that wireless router DI-624 works with VISTA and that no FW upgrade is required.
Additionally the 2 new packaged wireless cards that I have had for 3 years D-Link # DWL-G520 Revision B1 will also work with VISTA with a driver download v. 4.4. DWL-G520 Wireless 108G Desktop Adapter Vista Driver Ver. 4.40 or Later for Rev B only.
So based upon my research the intermittent connectivity issue VISTA SP1 based when offending code interacts.
I'll have to research further and determine if the "offending code" is internet based or something that is due to multiple code interactions from various sources.
Then I must determine if I can resolve the intermittent connectivity issue locally.

I found that the new cat 5 cable has a bad RJ45 connector and does not firmly snap in place.  It intermittently breaks connectivity and then reestablishes it.
 
I have awarded the points to Sappbrosts re: his suggestion.