It won't do anything to your computer unless you tell it to - and it's easy enough to use .... just make sure you don't have c drive selected
any disc operation is system level .... so with problems you have to use system tools
back to the drive
Assuming that you are running XP or Vista on a reasonably new machine there shouldn't be a problem.
however 8gb could cause compatibility issues on some older Mobo/ processor / bios combinations.
but if a newish machine .... it sounds like the drive is faulty
the makers will always pre-format the drive so it's ready for use (usually fat32)
but
if you've only been able to half format the drive .... the partition table is likely gone so the drive is already broken .... generally speaking you need to use a utiity to force partition/format the drive ..... which is where the knife comes in.
an alternative you could try is
windows' own disk management utility to create the partition .... then reformat
or
http://files.filefront.com/usb+formatexe/;6636 264;/fileinfo.html