Vanishing Hardrive

My drives disappearing

I am on a dell dimension with a floppy A : hard disk c : and cd burner e :

2 hard disk d : dvd player f :

the problem is there

At startup regularly windows freezes with the hourglass not moving at all

Only solution a reset

Very frequently drives are missing sometimes it is d : sometimes d : and dvd player

A maze at Dell show me a trick go to the bios restore default parameters and restart well it works sometimes and sometimes not

Last night it took me an hour before I could made a clean shut-off the d : drive was not even seen in the bios. Suddenly with no warning after a series of blue and datk screen windows told me that it was doing a an scandisk on d : the one who did not even existed 10 minutes ago miracle everything was back in normal but is annoying

I noticed that this problem is particularly frequent as I am fighting a particularly resistant spywrare- malware after an hijack cleaning or a ad-aware clean

Is it virus related that gives bad shut-off is my computer dying ?

Help appreciated

Thank you jr