WiFi problems (read before suggesting I haven't)

I use a 2008 black MacBook, Intel Core2Duo.
Need more specs, just ask and I'll provide them

Here is the problem. I have had WiFi problems for a while now but it isn't dropouts out of no where. It seems to be when I am either so far from the router or when to many things come between the two points it drops the signal.
My proof that is in my MacBook alone. When I'm in my home, I keep my MB in the room with the router and incur no problems but take it out and the signal disappears and won't be picked up. It isn't the same for my iPad2 that picks it up and works just fine any place in the house.
At my work, I have an associate with the same exact MB I have that we bought at the same time in 2008. Her's will pick up the signal of my property's free wireless in the back office, but mine will not.

I want to say it's a firmware update that is needed or a setting that may be on/off that is making it difficult. Truthfully, I know it may be the MB itself. But to have it work just fine in a certain distance while others work just fine outside of that distance doesn't seem like a hardware issue.

Any help will be much appreciated! Ask for anymore info that I can give that will help. Thank you in advance.

J. Smith

 

Thank to the two that responded.
I can't be definite when it started but it definitely wasn't in that condition at first. It's not normal for me to let something happen to it. I'm far from reckless.
Do either of you two, or anyone else, know of a video or instruction that can give me an idea of what I'd be getting into before diving in head first?

J