Possible Duplicate: What to do if my computer is infected by a virus or a malware? What's the best way to clean a computer with multiple accounts infected with spyware, viruses and malware? Should you install and run software to remove the infections on each account? If you install the software on one account, will it clean the entire computer including each account? For example, some programs like CCleaner will install only on one account and not offer the option for all users (accounts). Does this mean the program will clean the entire computer including other accounts or do I have to install CCleaner on each account to clean up each user's account?