Multipartite viruses use a combination of techniques including infecting documents, executables and boot sectors to infect computers. Most multipartite viruses first become resident in memory and then infect the boot sector of the hard drive. Once in memory, multipartite viruses may infect the entire system. Removing multipartite viruses requires cleaning both the boot sectors and any infected files. Before you attempt the repair, you must have a clean, write-protected rescue disk.