I'm trying to delete a virus program and install another but the AVG antivirus program that I thougt I deleted and can't find in my files keeps sowing up in the install phase of my new antivirus program (iolo antivirus)

When antivirus programs fail to uninstall, trying to uninstall them manually can be a real pain -- and it often won't work because they're not designed to be uninstalled except using the uninstaller. The very best way to deal with this is to download AVG Free:

AVG Free - Download Free Antivirus and Antispyware for Windows XP and Vista

Install it and immediately uninstall it and reboot your computer. With a little bit of luck, everything should be gone.