I reinstalled Windows to fix another problem earlier today, and have made another. I now have a rather large block of my HDD that I cannot access because i did "Keep File system intact" so if says My C Drive is using 146GB, but I select all items in there and it's only 57GB. it kept everything i had in the "Programs" folder, but I had stuff on a desktop folder that it did not re find. I get the feeling that these "invisible" files are eating up the space. Anything i can do?

ewwwww... I had a problem like this a while back, I was planning on using getbackdata, but it takes forever for the algorithim to see everything and I got lazy... but you can give it a shot and see if you can recover it:

http://www.runtime.org/gdb.htm

Otherwise try running a repair? Seems like there is something wrong with the addressing of the drive..

Go to <My computer> right-click on your sistem drive and select Properties. Click on Disk cleanup, select more options tab and click on the last one (System Restore). Say Ok and it might solve part of your problem.

After much digging finally accounted for all hard disk space. This is for Gateway with Vista but I'm sure the same applies to other systems.

320gb nominal = 298gb actual (standard, due to round-off)
10gb recover partition d: recover from crash
43gb system restore (15% of c: drive .15x(298-10) = 43gb), restore to previous point

To add up used files:
open c: drive, select all, right click- properties CAREFUL NOT TO DELETE
Go to system information for virtual memory (set aside on hard drive): start-all programs-accessories-system tools-system information. This is a few gb

For reference info on system restore: Start-Help & Support-Security and Maintenance-Backup and Restore (back up your files)-(see also)