Have you ever powered on your computer and found out that the cd drive icon is gone?
Or the wireless just would not connect?
Or the help is no longer working?
Or the dvd-ram drive is now seen as cd drive?
Or the system is now acting funny?
I will tell what I usually do after exhausting all other possible options, I go to Start, Programs, Accessories, System Tools and System Restore, I choose 'Restore to an earlier date', then choose a date (closest to today) that I am most certain the computer was working great.
This miracle working tool has saved me so much trouble a lot of times, such that whenever I am happy with the way my laptop works, I go to maually create a restore point. Actually, restore points are automatically created when an application is installed or uninstalled, though not always so for all applications, but you must have the system protection enabled/on.