[MTJR]

The only true way to speed up a computer is to put more memory in it. Disk cleaning, etc. is just robbing Peter to pay Paul. In other words, you're not really solving the problem.

The files that Windows shows when you hit "Disk Cleanup" should all be safe to delete. If you have a large amount of Temporary Internet Files then getting rid of them may go some way to improving the situation.

As you won't be changing any root system related files then a Restore Point probably won't be needed. A back up would be more helpful should things go a bit awry.

In short, more memory is what you need.

John