Okay.. I think it's a heating issue... And it's been happening ever since I cleaned my CPU (used a hair dryer on "cold" setting from about three feet away) which seems weird.
I downloaded CoreTemp and it showed me my temperatures were up to 80-90 degrees Celsius... Is there a way I can cool down the processor more than just by using the fan?
That's not cleaning, that's pushing the dust further to the fan making it worse for it to operate on high RPM.. Yes there is cooling pasta (thermal compound) for CPU's, which is inserted under the actual fan thermal outways and on top of the CPU..
Here's actually a way to install it correctly ==>
http://youtu.be/EyXLu1Ms-q4I'd also recommend to replace the battery because it may have completely discharged... (Seeing as you see the CMOS check error each time you turn on your computer!)
Another thing to do is, Hit Windows Button (on your keyboard) together with 'R', it will prompt you to a command typing... Write 'msconfig' on it and press enter.. Now, it will open a window with few tabs, go on the last one which shall be named start-up or whatever (not identical because I use greek OS..), and from there you can see almost all the processes that are called to launch upon turning your computer on.. Make sure to disable whatever is not necessary and remember to never disable 'ctfmon.exe' because you wont be able to have sound / nor play GTA SA (as it requires audio in order to launch).