It sounds like your touchpad or mobo is broken. IDK how expensive it is to fix laptops since I don’t use them, but if it’s older than 3-4 years you shouldn’t bother repairing it. Just get a new one. I buy new parts for my computer around the 3-year mark.
Good tip from Pixel though. You could use the computer a while longer if your touchpad is the problem and you buy a cheap USB mouse.
I’ve never had heating issues with a desktop. I think that is mainly an overclocking thing. Or an I-didn’t-clean-my-computer-for-three-years thing. 
I love my desktop.
I have an HP laptop and it has worked well close to three years. I did have to install a new BIOS once because my keyboard was not working.
Most laptop heating issues result from improper use. People sit them directly on their laps and block the intake and output ventilation ports, causing the device to run over temperature. It is designed to sit on a flat surface with a slight gap underneath allowing proper ventilation. We have several of these in our home for Mrs. Pixel, The Princess, and myself for our laptops:
http://www.amazon.com/HandStands-Laptop-Lap-Desk-Comfortable/dp/B0013KLL72
Using these will prolong the life of a laptop as frequent and sustained overheating will cause premature malfunctions.
Pixel.
I want to replace the keyboard and mouse for my home Mac…
how about investing in a macbook? I bought one last year and I pay in small monthly bills.
I’m inclined to agree. I sold and repaired computers while going through school. Four years is pretty much the lifespan of a laptop for cutting edge (e.g. game playing, media manipulation) use in the fast-changing digital universe… though one can load them up memory beyond what they came with to get another year or two out of them (sort of).
Ditto. A neighbour brought me one with a cooked mainboard. Even if I could find a replacement mobo for it, the cost of the repair would exceed the cost of replacement and they’d still have an older, underpowered system.
Pixel.
