What do you mean by "system registry".
And what does "System Mechanic" do ..??
Click on START
Click on RUN
Type REGEDIT
Hit OK
That is your system registry.
If you want to play with it, be very, very carefule. If you want to get rid of AOL (likely loaded on your machine when you bought it but definately bad to have on it) try this.
Click on EDIT
Click FIND
Type in AOL
Click FIND or FIND NEXT
DON'T delete anything in your registry if you don't know what you are doing. Entries will show up under AOL that may not be related to AOL
And if you have AOL and use it, definately do not delete it.