chkdsk won't run/Roxio/DLL shared corrupted files

I have gone through all possible procedures except going through the registry
to get the chkdsk to run at restart. I don't understand why I can't get this
procedure to work, my husband has WindowsXP on a older Dell Desktop and was
able to go through similar steps and was able to run the chkdsk. Even the
scannow could not be completed. I have no idea if by getting it to run if it
would fix the other following issues I have.
I also have RoxioShared/DLLshared corrupt and unreadable files. This
happened moments after choosing Install later for an update/upgrade.
I did everything possible to remove anything Roxio/Sonic even the clean
utility. Dell has said that I will have to reinstall my operating system. I
can't find any evidence that it is a hardware problem, I ran the Diagnotics
and I did get an IDE device failed...Blank Media or no media is present in
the optical drive OFFO:137B?I just want to have a better understanding of
how or why I have to reinstall my system which is only 3 months old. I have a
1521Dell Vista Home Premium.