|I sure hope you didn't pay much more an infected laptop with no CD/DVD drive?|
Probably the best way to proceed would be to completely wipe the hard drive & reinstall Windows from scratch. That way you'll be sure to be 100% virus free & working with a fresh install without a bunch of crap from the previous user/owner.
However, you're obviously able to get online so all you'd need to do is download a free AV program to a USB flash drive, install it on the laptop (is it a netbook?), then run a full scan from safe mode.