Does your computer feel kind of slow? It probably is, computers tend to mess up things...
There are two effective tools to get rid of the most common resource hogs they are both built in and can be started in the Start menu.
Disk Cleanup
This will clean your Hard Disk of trash, unused files and temporary files.
It is important because it reduces the amount of unnecessary files and makes your computer 'cleaner' to run. Use this tool at least ones a week.
Click on the Start Menu - Click on Programs
Click on Accessories - Click on System Tools
Click on Disk Cleanup - Click OK
When it finishes calculating what your can discard, a new box will pop up. Select everything (not the trashcan though)
Click OK.
It might ask you if you really want to delete all these file - Of cause you do! If you have several hard disks (other than C:/) you can run Disk Cleanup on each of them separately.
Disk Defragmenter
Disk Defragmenter reallocates your files in a more efficient, organized way on your hard drive.
The Disk Defragmenter will sort your programs back to their rightful places and order, so that your computer can find things quickly.
Click on the Start Menu - Click on Programs
Click on Accessories - Click on System Tools
Click on Disk Defragmenter
The Disk Defragmenter box will pop up.
Selected Drive (usually C)
Click Start
When it's done (it can take a long time), restart or shutdown your computer
It's okay to leave disk defragmenter running overnight then reboot in the morning.