If you use an Apple or Linux computer you can check out now and come back tomorrow. If you have a PC I have two excellent tools for your computer that will make it "faster than a speeding bullet, stronger than a locomotive, and able to leap over tall buildings in a single bound."
CCleaner is a great tool for taking out the trash, getting rid of unwanted programs, cleaning up your registry, and removing programs that slow your computer at startup. The function I use most often is the the Recycle Bin cleanup. More than just emptying the trash it also cleans out the temp files, the browser caches, and the internet cookies. One shot, all done. It is all wrapped in a user friendly interface that doesn't take a geek to understand but puts all the options under your control. Once set up it can run as easily as the regular Empty function but does so much more.
Every computer comes with games, trial-ware, and other unwanted programs that the maker includes "to enhance your user experience". This usually means that they got a few bucks for including this crap at your expense. With google running in one window and CCleaner in another I was able to check on each program and eliminate a couple of gigabytes of programs I had installed and never used or that the manufacturer had installed. For instance I found that I had a program that controlled a dialup modem. First, I don't have a dialup modem and second, there isn't even a land line to the house any more! 350 megabytes of space reclaimed just for that one.
CCleaner also has a similar program for disabling programs that automatically start when you turn on the computer. Every program wants to think it is so important that it should take up memory so that you don't have to wait an extra 3 seconds when you really do want to use it. If you ever do. Again, Google in one window and CCleaner in another allows me to check what each one does and then decide to disable it or not. This is especially safe since you are not removing the program and can re-enable it if you guess wrong.
Finally, CCleaner has a registry repair function that checks for missing keys, broken links, and other crud that builds up over time. Since this is all kept in memory it is just wasted space and possibly info that can cause errrors. CCleaner first scans and presents a list of issues. Then, with your permission, it makes a backup and fixes the problems.
I've been using CCleaner for a few years, on a few differnent computers, without a single problem. It's good stuff and it's free! You can make a donation and I recommend that you do if you find it as useful as I do.
Once you get everything all cleaned up it's time to reorganize. Microsoft has a disk defrag utility that is worth every penny you paid for it. It's better than nothing but just. Smart Defrag is so much better in so many ways. It's another free program that does a deep defrag rather than a superficial one. It will do a disk optimization as well as the simple defrag. Caution: the deep optimization will take a long time! I usually start it before going to bed at night so that the computer is ready in the morning. Smart Defrag doesn't seem like much as there is only one thing it does. However, it does it really, really well.
Try out both of these programs, your computer will thank you. If you find them as useful as I do make a donation to the authors. They will thank you.