I'm into music production, and I'm redoing my studio. The computer I had is still good, except that it's got a slow CPU and too little RAM. It has an i7 Q720 GHz CPU and only 4 gigs of RAM. Is it at all possible to take it apart and switch the CPU with something a little faster, say around 2.5-2.8 GHz, and up the RAM from 4 gigs to 8 gigs? Would it be cheaper to build a desktop computer with better components? Also, I had a recent problem with it over heating because the fan stopped working. I got the fan fixed, but it seems to be having glitchy problems like programs take a long time to open and it lags every once in a while. Is this fatal to my computer, or can I get the parts replaced? Thank you.
Processor replacements on laptops generally are somewhere between difficult and "will absolutely ruin your system" on the difficulty scale. Depending on your laptop's configuration, you may be able to add more RAM. I would, at the very least, suggest taking the time to clean out the ventilation, though you may have already done that while fixing the fan. The symptoms you describe sound like potential heat damage, which can be fatal, and replacement parts are likely unavailable or so expensive as to make the cost unjustifiable. In the long term, it sounds like you want to upgrade, so a budget for a desktop (or new laptop) may be helpful to solicit build suggestions.