I've had a question(s) regarding computer degradation going through my head for a while and haven't found many good resources for researching it.

1) First off, when is the virtual RAM/paging file on a hard drive used by Windows? Is it used when the RAM is full? Or does it use the Virtual RAM/paging file as intermediate caching between the RAM and actual hard drive space all the time?

2) If I were to run many applications on my computer at the same time and have a bad habit of doing this for the entire lifetime of the computer, does it use more of the virtual RAM/paging file than if I were to have fewer programs running? Just to note, the RAM never fills up on my computer but it is used heavily.

3) By extension of question 2, if the virtual RAM/paging file is used more heavily, would that result in rapid hard drive degradation?

I have seen a pattern among all of the computers that I have owned or used in the past 5 years. I am the kind of person to leave my web browser up with 40 tabs among other programs which will eat up 40% of my memory typically. Over time my computer will slow down, browsers start crashing, programs start seizing up or crashing themselves, eventually the computer becomes essentially unusable. I have been trying to rack my mind to come up with a solution other than to purchase a new PC to have it die on me in the next couple years as well. This is the only thought that has come to mind that might have a simple hardware fix...Windows ReadyBoost...Maybe? I'd like to be able to discuss this so I can learn something about all of the above.

Thanks.