i had a fully working computer until 20 minutes ago

Windows XP freezes at startup, whenever i click on my account it freezes at
"loading personal settings"

The only time i can get past the loading personal settings screen is if i
click my account as soon as the welcome screen appears.

Once i get to the desktop it all seems fine, but nothing will respond, one
time it did say "impropper shutdown VGA pool..." something about the VGA
pool, I am not sure at all what this means, but all i know now is the
computer is as good as dead!

I put the windows XP disk into the cd-rom and pressed the restart button on
the case, the computer restarts, but wont boot into XP setup it just goes
straight into the operating system, and the problem of not being able to get
passed the welcome screen occurs again, as does the problem with the desktop
freezing when i manage to get passed the welcome screen.

I am now completely stuck, I have put the hard drive from the computer into
my old computer (the one i am on now) and was hoping that i would be able to
format it through windows (right click format) or even through the command
line with format f: but it wont work

the hard drive has practically merged with my old one and when i view it
there are all my files on it that were in the root of the drive... Hijack
this, etc. etc.

i try to format and i get the following message in the command line.

"format cannot run because the volume is in use by another process. Format
may run if this volume is dismounted first. ALL OPENED HANDLES TO THIS
VOLUME WOULD THEN BE INVALID, would you like to force a dismount on this
volume Y/N"

I click Y to indicate yes and the following message appears

"Cannot lock the drive. The volume is still in use"

I then tried to right click on the F: drive and select format. this raises
the following prompt

"Windows cannot format this drive. Quit any disk utilities or other programs
that are using this drive, and mae sure that no window is displaying the
contents of the drive then try formatting again"

The problem is, i have just installed the drive onto the slave IDE and
havent opened any programs from it, all i have done is opened the drive to
see what was in it, i cant work out how i can format this drive.

I am stuck, i cant format through XP setup on the computer the drive should
be in as i explained earlier, i cant format in my old computer because
apparantly the drive is being used ?

is it just me or have microsoft made it impossible to do any maintenance on
your computer without the assistance of a tech who charges £2 per hour on
the phone?

anyone please help?