When your computer has slowed down in operation very gradually over a period of time a likely reason is a hard drive which is overloaded with programs.
Most of us download a lot of stuff from the internet either for business or for personal entertainment. Some of these programs can be very big these days.Since 300 and 400 Gigabyte hard drives have become popular many programmers have created very large programs. It is not uncommon to see programs of 50 megabytyes in size and can be a lot bigger.Twenty or so programs of that size will take up a gigabyte or more of room on your hard disc.
Few of us will limit ourselves to just twenty programs. Besides that you have all the usual applications using hard drive space. Email,photos and pictures,audio and biggest space hog of all--videos. Even a pretty big hard drive can over a year or two become pretty near fully loaded. You will then run into problems with slow operation of your machine.
The cure is quite easy--just have to uninstall a lot of material which you seldom or never use. All of us have programs which we downloaded because they seemed to be really worthwhile at the time. A year later many of them have never been used or almost never used. Get them off your hard drive now. You could store some of them on flash drives or even external hard drives if you feel that you really must. Get them off your hard drive and open up gigabytes of room. Doing just this will speed up the computer quite noticeably. You can also check out my website where you will find tons of information about fixing slow running computer.Slow computer