Utilities to test system speed and repair

I am looking for two utilities:
1) Benchmark the speed of my Windows XP system.
2) Clean up my system.

There are several utilities that claim to clean, repair, and speed up
computer systems, but how do I know if they really works? (Unless the
system goes from dog slow to speedy.)

I tried Ace Utilties and it seemed to work OK.
Are there any basic benchmark utilities and
system "speed up" utilities?

Thank you,

Kevin