I have been working on a friend's computer for a week now but I am running around in circles. It's a Dell Dimensions 5150 with Windows XP.

It started with BSOD'S at random. It wouldn't even let me do a clean install of Windows so the MBR was changed and couldn't get the CTRL-F11 (recovery mode) to work. Fixed that and did a recovery but now on startup when the Windows XP "movie" comes on (the first time you boot after install) it gives the PFN_List_Corrupt Blue screen. I ran the diagnostic cd that came with the computer but he can't seem to find any memory problems. The computer however freezes when running the Harddisc S.M.A.R.T. long self test. Is it save to say it's not the memory but the hard disc that is slowely dying?

Thanks,

YES, it's a memory failure OR the HD is not getting the updates to the pagefile properly written.

imo, memory is the most likely and running MEMTEST should show that.

I'd also agree that running MEMTEST (for several hours) is called for and a better way to test your memory then the diagnostic CD

I'd also recommend you look through your Windows Event Logs as it might have records or point to clues of disk, memory or other issues. The System Log is most applicable in your case. But advise you have a look at Application log as well while you're at it

To use standard Windows Event Log viewer tool: Click Here

If you'd like to try a Event Log viewer/management tool that offers some extended functionality (and some easy button clicks to look event log info up for troubleshooting) you can also See post Event Log Explorer.