--Chkdsk /f was run on re-start and booted to normal Windows. I didn't see that it identified any problems.
--Slipstreaming XP3 with my early Win XP disk seemed like a challenge (and I've not figured out this "burn as image" process). So I ran SFC scannow from the command prompt within normally booted Windows just to see what would happen (without any installation disc in the CD drive). It never asked for an installation disk, slowly did its file checking over 20 minutes or so, and did not report any problems. I hope this result means that none of the Windows files are damaged, though I wonder what it was actually comparing the files to as no installation disk was inserted.
--Newly downloaded versions of Avast and Malwarebytes then full system scan runs in Safe Mode found no threats or problems.
--Deleted temp files and am now running defrag which looks like it will change very little on the hard drive.
So, all seems good! No error messages or BSODs since removing the bad memory stick (and its partner). Though tell me if further checks are advised or if chkdsk or SFC scannow should be run differently than as just described.
Two questions remain:
Mchain--Is my understanding correct? You are advising temperature monitoring (and heat-sink compound if needed) as high temps may have lead to the BSODs and possibly to the failed memory stick (and would also put the processor at risk of failing)? Have to say that the computer is running more quietly since its cleaning yesterday (obviously a good sign, and a reminder to me that this should be done a bit more frequently than twice in 8 years!).
I will upgrade to two x 1 GB DDR2 PC2-6400 sticks as recommended for this computer by Crucial.com. These are "faster" than the PC2-3200 or PC2-4300 recommended in the Dell Dimension 4700 specs. Would anything be gained by filling the remaining slots with two of the original 256 Mb sticks which are PC2-3200 versus leaving those slots empty? That is, would the increase from 2 to 2.5 Gb RAM offset the reduction in speed by the addition of the slower PC2-3200 sticks? My daughter's computer is not used for intensive stuff, but for word processing, surfing, live streamed video and music. (My thinking is to buy Crucial, Kingston, Corsair or Patriot memory sticks from a well known seller like Crucial or Amazon rather than saving money on a lesser known brand or seller.)
Again, much appreciation for your help, Mchain and Essexboy. Three days ago I was convinced all was lost and that a new computer was needed. Now, I'll spend $36 and should have improved performance.
Bob