Could someone with computer knowledge, help me?

I've been noticing that in the last few weeks, that my computer is losing time, and I mean a LOT of time. I started noticing it about a month and a half ago. At that time the clock was a little slow, so I reset the time. Then I just kind of ignored the time, until a couple of weeks ago, where I noticed it was slow again. Then last Sunday I noticed it was about 10 minutes behind, so I set it ahead about 5 minutes. Just now, I noticed that it was 10 minutes slow, which means it's lost 15 minutes time in the past week. What could be wrong? Is it serious? My computer is still under the 3 year repair package I paid for when I bought it. Is this something that needs to get repaired?

Personally, if it is just losing time, that's no big deal, but if that's a sign of something worse, then I should probably get it fixed. Unfortunately, in order to get it fixed I have to take it to Best Buy and then they send it off to the Sony factory and it may take a bit of time before I get it back.

I do have a lap top, but I hate Lap Tops.

A perpetually slowing clock usually means the CMOS battery on the motherboard is near the end of its life. That's a cheap and easy fix for you to have done at most repair shops -- even laptops generally have their CMOS batteries accessible.

So, it wouldn't be worth it to send it to Sony and probably be without it for a couple of weeks, then? It's a cheap easy job, that can be done in a computer job? Cool. This computer shouldn't be needing a new battery this early. Oh, well....

This little program www.clearprog.de makes my computer run faster, it is free (if you download, you can select English Language).
Or, I don´t know your Computer, you have to insert a coin, so it will work?