Windows 7 using too much memory

I have encountered problems with Windows 7 using too much memory, but a reboot fixes the problem. This can be the result of a faulty driver. I think that, specifically, Comodo System Cleaner
was causing a memory issue. This may be resolved in newer versions of the program, so update it first and see if the problem persists. If it does persist, uninstall it and test again.

You can also go to your Device Manager and select View -> Show hidden devices. Expand "Non-Plug and Play Drivers" and uninstall any drivers that you think are unnecessary. Usually, third-party drivers are spelled in lowercase. If you don't know what a certain one is, google its name, and you should be able to find out.