I found this post at LifeHacker to be a good list of stabilizing Windows.  I knew somethings already, but some of the items were surprising to me.  The list tries to prove, or disprove, any misconceptions you may have.  Some of my thoughts:

• Who knew that Microsoft Security Essentials was really that good? I would have never thought that.
• I agree with being very careful with Admin rights and only use them when you need to.  Nothing else gives you more security headaches than some malware installed as Admin.
• Revo is a good thing!  Most Uninstallers leave lots of stuff behind.
• I’m glad to know that defragging is finally going away in the Windows 7/Vista world and beyond.  It’s been around too long.

Maintenance on your PC is something you need to do,  just like you need to do dishes, take out the garbage, etc.  Do it regularly, before things start smelling, er, crashing.