You didn't have to buy UBCD because it is freely available.
To know how all the tools on UBCD work, look at
http://www.ultimatebootcd.com. Scroll to the bottom until you see "
Tools currently included in the Ultimate Boot CD are:"
For you, the right section will be "Anti-Virus/Malware Tools". With the programs listed there, you can remove viruses but the definition files are out of date (won't detect new viruses).
Click on the links of the other programs too, to see what they can do.
If you have indeed viruses, you probably can better surf to
http://www.ubcd4win.com and build your own bootable graphical windows environment. If you don't know how to build it, see
http://www.ubcd4win.com/howto.htm.