IDE or SCSI drive?

if it a dell or hp or compaq they have the model spec online. you could also make a boot usb stick of hirem boot cd and use the anti virus tools to remove the virus but to also use hd tune to read the bios info of the hard drive. you get the drive model and ser# then google the model number info. the easy way is just open the side panel up and look at the drive cable conenctor.
sata the newest drive connector are small and look like the letter l they look like small audio plugs for cd-rom drives. ide cables are 40 pins gray ribbon cables. sata are 80 pins. most home mb were ide not sata as sata drives used mostly in servers and work pc. on mb you shuld be able to read ide 0 and ide0 or primary ide and secondary ide on the mb. with a flash light. if the system is a home build unit go to the mb vendor web page and look at bios size limit for hard drives. hard drives got so large so fast that a lot of older mb cant see the newer one tb drives. some have 500-300g drive size limit in the bios. your better off looking into seeing the max size your mb can use before you buy one and fine it wont work. with your drive replacment look into getting a dvd burner bulk drive. most times there the same cost as a standard cd-rom drive. with the dvd burner you be able to play dvd on your system and burn larger disks then the 700m cd-roms.

Thank you. It's a Dell. I'll look up the specs this weekend.  

home pc the older ones were mostly ide. at some point sata started showing up on the mb. the newer mb now are all sata and no ide.

Determine the drive's model number and then Google it. Just about any HDD utility will be able to do this. You may even be able to see the model number during the POST.

Thank you. It's an older Dell computer, so I'll go on dell.com with the model # (Dimension V400). I did the same for the Win32 sound driver!