Why Do Computer Become Slow?

Have you ever experience that your computer become slower and slower with time?

It gets longer to boot-up, applications become sluggish and file transfer take ages.

One possible reason is that the hard-disk has been filled with fragmented files, caused by writing and deleting. Try defragmenting the hard-disk to move the files nearer to one another and also away from the edge of the hard-disk.

Just follow the screen:

Run defragment for c and then d: