Hi Derek:
Not likely a virus. Here's how to check.
Re-boot your system and as soon as the first screen appears, keep tapping the 'del' key and this will put you into the BIOS.
Scroll down to 'advanced bios features'. Your bios may be different from mine so you may have to some exploring to find the next step.
CAUTION: If you don't know what something is -don't change it.
You should find 'first boot device'. You should make this the 'A' drive, in case of trouble later with your system.
'second boot device' you can set as 'C' drive. Next can be set at 'CDrom' if you wish.
There is no need for setting the 'D' drive as any boot device unless you have dual boot capabilities.
Hit 'F10' to save and boot.
Hopefully this will solve your problem.....Cheers