Stop using it on your bed.
But really, how old is it? Do you have animals, smoke, live in a dusty environment? Sounds to me like it's time to get a proper clean out. Unless you
feel comfortable opening it up (which is a pain, trust me) it might be time to take it to get a good cleaning and fresh application of thermal
Oh, one last thing, *vacuum all of your vents and openings. And no, this isn't going to cause a static charge that will destroy your system. Now, I
wouldn't vacuum a motherboard, but it's safe to vacuum the case openings, I do it weekly on all of my electronics.
*Don't use compressed air to clean it, that just blows crap back into your case.
Make sure you don't have too much starting with your system.
Type msconfig into the start bar, go to your startup tab, and make sure only programs you want running are starting with the system, such as virus
protection (other than that, I'd disable all).
Download and run Spybot search and destroy, just make sure not to install any extras such as tool bars.
No tool bars!!! Your browser should have as few extras as possible, since this just overworks the system, and degrades your systems performance.
Check out this page, good information for keeping a well maintained system.
Life hacker "How to speed up, clean up your system"
How to speed up, clean up, and revive your mac
13-8-2013 by Chargeit because: (no reason given)