It will not damage your PC. But it is not a very smart idea to do that because it won't have much effect if you clean your registry every day or if you defragment your disk.

Our advice is to do that:

-Run a full system scan with a good antivirus and antispyware and just let them to scan in the background for you. ( enable them)
-Do once every 2-3 weeks a HDD defragment, windows registry repair etc.