There are many Junk file cleaners available and i believe use Disk Cleanup which is inbuilt utility of window.
I worked at the store in high school, and am still working at it part time. Junk Files are the main reason for Free Disk Space and PCs Slow Speed. After that's done, Ghost an image of your drive to another source, such as another computer or a set of CD or DVDs, or another hard drive.
Install all your latest hardware drivers, install all the main software you need (Office, Anti-virus, DVD/CD software, stuff like that) and update it as well, and then install all of the Windows XP updates. Junk file from your devices with Windows, Mac, Android or iPhone, keeps your space occupied and in most of cases it is about unwanted junk. If you can't uninstall the programs you need to without shared file errors, or it's too much spyware to remove, or if you have a virus.my recommendation would be to reload Windows XP. I think the people on this thread have pretty much diagnosed your problem. Low and behold, they had close to 50 processes/programs in startup. People would bring their computers in complaining about "slow speed" or "freezing" with a brand new computer, and I would put it on the bench and start it up. I use to see this all the time with customers. I'm running Windows XP SP2, with a 30 GB Programs File folder, and I only have about 20 when I start up. 45 resources is an a lot of resources also. You don't need it to scan every time you boot up or run live update either. Other then that update your drivers especially motherboard ones ) Click the box that says don't ask me again and click yes. You will get a box after restarting that says do you want to keep this configuration. Then uncheck the boxes of junk you don't need. Then go to the tab caled startup and you can see most of the stuff running automatically on your system. Something must be running when you start your computer I think. I have heard that switching to SP2 can slow you down but that has not been my experience. If you have the first one you are gonna have to boot in safe mode to get rid of it and run Spybot and AdAware SE to get rid of it. Those are some I have noticed killing people's computers. If there is a process that seems to be named random letters and also some are capital and some small letters. Try looking at your running processes and see if you have anything that looks wierd. Your PC will then delete all the files that you selected. Click the Delete button to delete the files. After this utility scans the drive, it presents a list of junk files. This can be accomplished with a Disk Cleanup utility. If you used it from day one then that's pretty wierd that it would get dogged out. The first step in cleaning up your computer is to remove junk files from your hard drive. My main question is whether you started using Firefox last week or have been using it for the whole two months.