As far as Im concerned, and most will agree.
A full updated scan with a good anti virus ( I use security essentials)
A full updated scan with malwarebytes
A s full scan with Spywareblaster is all that is needed for Malware protection.
For maintenance
To maintain your computer
10 Tips on How to Properly Maintain Your Computer
Steps that I did not notice on the guide include:
Running a scan disc before doing a defrag
Using Microsoft Security Essentials and Malwarebytes.
Making System Restore points, at least once a week
Makaing a system Image once a month (varies by user)
Not relying on your A/V common sense, should prevail. You know of many sites can cause a problem.
Do not use any reg cleaning or optimizing software.
Download and use Ccleaner about once every two months. Untick any registry entries.
http://www.piriform.com/
If you follow these instructions, you will be trouble free for a long time to come.
Be sure to back up your hard drive about once a month (varies by user) and to keeep system restore points up to date.
Optimize Windows 7 For Vista Too