Plz Help me. !!!!!!!!!
If you do nothing to maintain your (or any) PC, over time it will fill with files, references and data that it doesn't need, or used to need but doesn't any more.
So it takes the PC longer to find the files it does want.
The effect will be to make it start up more slowly, shut down takes longer, and in fact everything takes longer, as the 'junk' files take up progressively more space on your hard drive.
The computer isn't 'slower', it is just having to spend more time doing things it shouldn't have to.
If nothing else, have a look at;
(Even better, try them, most programs are free).
To same me from repeating myself, you from searching and the board from duplicates, I'd refer you to my relevant post #14, currently the last one, in thread:
What's good, you don't have to read the entire thread, just that post.