Gaming Wuts wrong with my computer?

[Luigi2012SM64DS]

I just uninstalled windows 8 transformation pack. and i hear my cpu fan turn on all the time what did i do? also i was disabling indexing service but i shutdown the computer. is it indexing service and how long is it going to last?

 

[Jehuty25]

Did you open the case to see if there was dust?

 

[Luigi2012SM64DS]

i opened it a month ago and yes it was full of dust.

 

[Originality]

Clean out the dust, all of it, and your system should be quieter for another month or two.
Actually, how loud the fan gets isn't that important - check the temperatures (using SpeedFan or Speccy). That'll tell you (and us) if something is wrong with your heatsink/fan.