Lost 4 Gigabytes

also know the difference between file size and size on disk
Size Vs Size on Disk

Size refers to the files actual byte count. Size on disk refers to the amount of cluster allocation the file is taking up.

Drives are organized by fixed-size units called clusters. The size of a cluster depends on several factors, the most crucial being file system and partition size.

Some background to help you understand:
Back in the days of DOS and Win95, the only usuable file system was FAT16 (also known as FAT). Because hard drives were so small back then (1GB was considered HUGE), FAT's limitations were minor, one of which was the limitation that the maximum partition size was 2GB.
With FAT16, the cluster size within a partition was determined by the size of the partition. Here is a chart showing the default cluster size for various FAT16 partition sizes:

Drive Size FAT Type Sectors Cluster
(logical volume) Per Cluster Size
----------------- -------- ----------- -------
0 MB - 15 MB 12-bit 8 4K
16 MB - 127 MB 16-bit 4 2K
128 MB - 255 MB 16-bit 8 4K
256 MB - 511 MB 16-bit 16 8K
512 MB - 1023 MB 16-bit 32 16K
1024 MB - 2048 MB 16-bit 64 32K

Now, with small drives, this wasn't a problem because partitions were small. Once drives started growing, the cluster size issue became problematic.

Here's why:
When you write a file to disk, the smallest unit it can take up is 1 cluster. If you have a 1024MB (1GB) partition, and the default cluster size is 32KB, a 1KB file will take up a 16k cluster.
Since you can't have more than one file occupying a cluster, the remainder of that cluster is considered wasted space. In this example, a 1KB file is taking up 32KB of disk space, and wasting 31KB of that space.
Say you have a 68KB file. That file will be written acrosss several clusters, since a cluster is smaller than the actual file. Thus, a 68KB file will take up 2 full 32KB clusters, and 4KB of a third cluster, while also wasting 28KB of that third cluster. While the file is only 68KB, it's taking up 96KB of disk space.

As you can see, with a lot of small files, you can waste a ton of space on such a drive.

To remedy the situation, MS unveiled FAT32 with the introduction of Windows 98. FAT32 not only allowed for significantly larger partition sizes, but also reduced the default cluster size dramatically. Under FAT16, a 2GB partition used a default cluster size of 64KB. Under FAT32, that was reduced to 4KB. A 16GB partition only used 8KB clusters, and up to 32GB uses only 16KB clusters.
As you can see, the savings on such large drives can be significant, resulting in more usuable drive space.

With Windows XP, the home user was introduced to NTFS. Under NTFS, a 1GB partition uses 2KB clusters, and anything above that up to 2TB (terabytes) only uses 4KB clusters.

So, the reason you're seeing that difference is because when you select properties, the Space On Disk reading is accounting for the wasted space attributable to the cluster size on the disk.

Note: MS has a chart with the cluster sizes listed on TechNet (http://www.microsoft.com/technet/treeview/default.asp?url=/TechNet/prodtechnol/winxppro/reskit/prkc_fil_lxty.asp).
Ref: http://forums.aliensoup.com/archive/index.php/t-6985

I believe the page file is handled by Windows XP itself, have no idea about it's size.

And by reading this info here, I presume there is no way to handle this "problem"?

One gigabyte is equal to 1,024 megabytes. Gigabyte is often abbreviated as G or GB.

Hard drive maker, 1 Gig = 1000 Megs
Windows, 1 Gig = 1024 Megs

When you look at hard drive, like maxtor. It shown 1 G = 1,000,000,000 bytes. You already lost something.
When you partition the drive, you already lost some more.

There are no partitions on my Hdd.

And in addition, I used to have SP 1 installed last week with almost the same software & games but back then total free space was something like 29 GBs.

Have you emptied the recycle bin? cookies in temp. folder, office setup files, etc. Right click on C drive, choose properties, then choose disk clean up. Make sure you check mark all of them, then clean up .... see if you can recovery the lost G. 4 gig lost is a lot.

documents and settings/your account name/local settings/temp.
Look in that directory and delete everything there.  Can be several GB there alone.
WHile you are at it, delete everything in Internet explorer cache -- start, settings, CP, internet options, temporary internet files, delete files.  This will probably reclaim at least 1-2 GB of the "lost" space.
Also under windows/downloaded program files, there might be 1GB or so there too.

If you would use "Treeview" you would instantly find where this excessive usage resides -- great program.

Used an IE Cleaner which totally wiped IE related stuff.

Disk also cleaned; Prefetch folder, Temp folder, System Restore, Downloaded Program Files, etc. all deleted.

Still missing the 4GBs.

Please see the link below:

http://www.langa.com/newsletters/2005/2005-04-21.htm 

the best way to know where everything went, is to install from scratch, and note the free space after each install.
>>  The installed software & games and such take around 7 GBs or such.  <<  how big can the difference be here?

Installing from scratch wont make a difference since I know my computer well enough.

Windows XP SP 2 takes around ~1.8 GBs.
World of Warcraft takes around ~4.7 GBs.
Installed Software takes around ~400 MBs.

Cant find any other files in my computer, not even if I ask to show the hidden files too. System Restore is clear.

The only thing I can think of is the updates Windows XP SP2 downloads from Internet which I dont have any idea stored where.

maybe a 4 Gb partition (can be hidden)

No partitions were made by me and personally dont think Windows XP SP2 can partition a HDD without asking :)

where does it show the 37 Gb ? in the bios, or disk management?

Havent checked BIOS, Windows XP says 37 GBs.

do me a favor, and check what shows in the bios ?

>>>>meaning that the 4 gigs you are saying that are missing are actually being used by the OS.

how much RAM do you have.. usually your pagefile is 1-1.5 times the ram.. you can check this two ways.


1) by right clicking my computer and selecting properties, then clicking advanceed tab... and going to Performance (settings) clicking Advanced (again) and down at the bottom you can see the total paging size (you can change it there)


2) you can double click my computer, click tools (top)/ options, select view, the select show hidden files  and folders, uncheck hide extensions..., uncheck hide protected... click apply

then goto the root drive of C: you should see your pagefile and size.. (view select details - or properties of the file..

Don't forget Hibernation .. if enabled it also uses space ..

Page file is ~2100 MBs which seems to be the part of lost 4 GBs (if it ever counts as a real file?)

its the OS that you're seeing take up the space.

ThanQ

It seems to be the page file and the OS thats taking the space.

Tried to be as fair as possible while distributing the points, thank you all for your ideas :)