Avast Cleanup is a service offered by the Avast antivirus software company. It is designed to clean up your computer by removing junk files, optimizing your system settings, and fixing common problems. One of the great things about Avast Cleanup is that it can potentially speed up your computer's performance. If you have been noticing that your computer has been running slower than usual, then Avast Cleanup may be able to help. The service can also help free up space on your hard drive by removing unwanted files. In addition to improving performance and freeing up space, Avast Cleanup can also help fix common problems with your computer.