Yeah, the program is a bit bulky and doesnt perform as well as smaller better programs. Download CCleaner. It does some of what System Mechanich does, but alot faster! I use the combination of these programs, which IMO is a better equivalent to System Mechanic.
CCleaner
Ad-aware
Wise Registry Cleaner
And if you want, you can also throw in AVG antivirus.
Just google them, they are all free to use.