Installed 2 used sticks ram matched orig. manuf., speed, size and ecc. bios recognized, win recognoized.
Installed new video card and software. operation good win recognized drivers.
Installed new dvd/cd drive. operates good.
Cleaned out old files, off loaded all good files to external hd.
Determined original xp install had been "fixed" preiously by use of oem disc not original mfrs.
(I believe this caused a win validate tool failure which prevented further xp updates.)
Obtained original xp from owners, reformatted hd with original xp sp1. results good.
Updated xp to sp2 via microsoft. results good.
Updated xp to sp3 via ms. results good.
Installed ccleaner. operated without problem.
Installed avg 8.5 anti virus. updates good. scan good.
Loaded comodo internet security...did not install to avoid conflicts for another program installation.(S.O.S.)
Installe Switched on Schoolhouse program. Install good. operation good.
Install comodo internet security. failed to update, removed failed install, Download from Comodo updated C.I.S. Installed ok updated ok scan ok.
Ran Avg scan maybe 3/4 through got BSOD windows shut down...UNMOUNTABLE BOOT VOLUME.
Try to re-boot using disc in cd, tried last known safe, safe, stc. same results
Try re-boot again , this time repair using chkdsk...system froze @ 25% allowed to remain overnite...no change.
Turn off system. restart. New response Error auto-sensing primary hard disk drive 0 press f1 to continue f2 to run setup.
Bios can be entered. hard drive is now seen as 0 mb and not installed inboot order. ram still ok 1024
Cleared cmos, swapped HDD cables with known working, removed battery for extended periods, checked all cables, all cards...no change
Tried re-boot from xp disk in windows repair... NEW response The path or file specified is not valid. the C:\> prompt cursor does not blink.
Now I have swapped in two old working xp used hard drives and get same response in the Dell. Here's the kicker, when I re-installed these old hard drives into my other old test rig I'm getting the Error autosensing hard disk drive on this computer now too.