First off, welcome to Netpond
no reason to be shy around here
About the Viruses, if the infection is bad I'd just reinstall your O/S(Windows I assume) since you never know what will be left behind after an infection(if one even exists), you are planning on running a business on the PC afterall, if you can't or don't know to do that grab yourself a free trial version of
Kaspersky AntVirus, although I don't use an AntiVirus you said you might be infected so try it and make sure that you're not.
After that ditch Internet Explorer and download and install
Opera as a replacement, then you'll wan't
a firewall(Sygate Personal Firewall)
That's just the basics but unfortunately there is alot more to securing your computer
hit me up on ICQ if you need any help or just ask here