Kingsoft Pc Doctor

Software containing the work ‘doctor’ in the name is usually crapware.  Kingsoft is an exception to that.
The software is smooth, works incredibly fast and reliable.
It scans, optimizes and protects the way it should.  (unlike some high-prized commercial applications -cough- symantec -cough-).

There are plenty of summaries online to find out what this software can do for you, but I can assure you it’s great.
Test it out yourself, get it at http://www.kingsoftsecurity.com/