What can be used to brighten up my pc

Solution
Are you talking about the PC hardware being brighter or the stuff on the LCD screen?
Custom-Windows-7-Desktop.jpg


and to run the PC at faster speed you can put it in a car and run it via UPS!

..no seriously, what mr51 said.
 
For something more personal or unusual:

http://www.wincustomize.com/
The 2nd row shows the categories of add-ons you can chose:
Window Blinds / Object Dock / Icon Packager / Wall Papers / Deskcapes

It's always a good idea to plan things out carefully so it all 'works together' and looks good.
And you don't want to slow down your system too much by adding resource intensive tasks and gadgets.