Computer Stutters

Hello everyone, . I have a weird problem with my computer performance that I am hoping to get help with.

I have found in the last few weeks my computer has been very slow, but not in a way that I am used to. Whenever I use certain applications, rather than responding instantly to any input I give, whether it is by keyoard or mouse, my computer frequently pauses/freezes for a second or 2 before continuing to run the application. For example, I may be playing chess and as I move my piece to the next square, it may freeze the piece in the middle of the move for a few seconds before continuing and completing the move.

During the "freezing period" I also notice that any input I give during this time gets read by the computer and applied after the "stutter" is over. For example, I may be typing a word quickly, then look up to notice that halfway through the word the computer froze, yet after a few seconds when it has resumed it goes ahead and writes the rest of the word that i had been typing during the stutter.

Im not that computer savvy so havent tried any remedies yet apart from a defrag that didnt help matters.

I have over 100gb of space left in my HD so memory isnt an issue

Thank you