Recently, my PC has been veerrryy slow. In the lower right hand corner, every now and then, an alert will appear that says "Virtual Paging Memory Low" and that I need to increase my minimum virutal memory. I went to help and tried to look it up and fix it, but that is too complex for me!! I consider myself moderately computer saavy, but I was completely lost. Needless to say, whatever I tried to do did nothing. Weird pop-ups also appear, but they say they are from Internet Explorer and Windows. I just ignore them. Sometimes I got alerts that appeared legit that said something along the lines of the memory being too full and that some requests for memory from some programs may be rejected. I also got a popup when trying to open up iTunes that something was wrong with my my audio configuration, however upon checking my speakers, etc were all registered and recognized as working by my PC. Strange....
I downloaded CCleaner (before even finding this) and tried to clean up some temp files and what not, but my PC continued to run slow. I really got frustrated when trying to run programs and they sudden froze for no reason (ex: iTunes).
My parent's PC somehow got a virus, and they did this cleaner. Thinking I may have gotten a virus myself, I thought I would try it, considering they said it worked well for them.
I download music and have TONS of it on my PC which all goes to iTunes. I deleted songs I no longer want and I also went through and deleted all programs I no longer use in attempt to speed it up as well (obviously did not work).
I just completed this whole cleanup...I'm assuming it worked

How often should this be performed (or use of any of the cleaner programs?).
I also have a laptop that is somewhat slow..should I also do this process on that as well? My laptop randomly shuts off, but I have a feeling it has something to do with the battery (the bottom left corner of the laptop gets extremely hot after about 30 minutes of use). Can you give me some advice with that?
Thanks!!