I have a D510 around here somewhere and I've seen that specific issue...
and it was another case of "when in doubt presume the OS is corrupted due
to a Geriatric hard drive"
The real "Issue" with a D510 is that it's an older notebook that uses an IDE hard drive and at current pricing....
Let me phrase it this way, the ONLY IDE notebook drive currently offered for sale at Newegg is an 80Gb Western Digital for $129.
for not much more than that I can buy a Refirbished E6400 "Buisness" notebook with windows 7 preinstalled and the computer will have a 160gb SATA drive already installed.