Breaker Problems

I have a kitchen breaker (20 AMP) that I have recently started to have problems with. The only thing on this circuit is a microwave and now exterior christmas lights which are plugged into a GFCI. It just started to kick when I hooked up the christmas lights. The breaker would kick if you tried to run the microwave along with the lights being on. After it tripped several times we realized we could not run both. A time or 2 it tripped while trying to use the micro. so we left the lights off right after it tripped, flipped the breaker back on and ran the micro, it acted as if it was getting only half the electric needed. Due to this I have moved the micro. to another circuit and is now working fine, but now my christmas lights wont work. I have replaced the GFCI, flipped the breaker on where the GFCI reset light flashed a quick second then went off. I tried to reset to no avail. Could this possibly be a bad breaker and how do I tell if it is bad. Also how do you replace a breaker? Any advice would be greatly appreciatted, Thanks

 

Is the breaker a single-pole (1" wide), or is it a double-pole (2" wide)?

 

It is a single lever , approx.1/2" wide at lever by 2" across.

 

Be sure you are turning the breaker "off" first then "on”. This is the only way to be sure the breaker is getting reset properly. You will need a tester and know how to run it safely while working in the panel, if you are not confident enough, then don't attempt to try and fix it your self. Test the voltage leaving the breaker you should have some where around 120volts, if not then replacing the breaker would be your first choice. There are several types of breaker boxes, so to advice you on how to replace it would depend on the type of box you have.
One thing to keep into mind around Christmas time is not to overload general receptacles around the house with Christmas lighting next year might be a good time to add a receptacle outdoors that can carry the load without effecting other receptacles in the house. Christmas time for everyone should be one time of the year that electrical awareness should be at it's highest.