How to get rid of viruses?

hi,i have made a mistake by searching on the web not protected with anti virus security,I'm wondering if getting rid of these viruses is just wiping the hard drive or a system restore.stupid of me i never back up any files so I'm kinda tempted of doing a wipe of the hard drive, if so i wouldn't know how to get my default programs back on,my computer is custom made by my brother's friend and he only gave me windows 7 to keep on me.so if i did get it wipe would i have to get him to reinstall the programs back on?my computer is infected with spy ware, i decided to unplug anything going to the tower of my desktop and unplugging it from the power bar.I do not know how to approach this