I bought my MacBook Pro about 2 years ago. Within the first week or two of use, I had intermittent keyboard problems. I'd be typing away and all of a sudden the keyboard would cease to function. A minute or so later, the computer would recognize the keyboard again. I solved the problem by taking the battery out and putting it back in. I have no idea why that worked, but the problem disappeared completely.
Fast forward to now and the problem has returned. Yesterday I was typing and all of a sudden the computer wouldn't take input from the trackpad nor would it recognize keyboard input. After rebooting the computer it told me that it couldn't find the bluetooth mouse. I've never seen this message before and have never used a bluetooth mouse with this laptop. In fact, I've connected a mouse only on rare occasions. However, I do have a USB mouse and after plugging it in, this window went away and another one came up telling me that the computer couldn't find the bluetooth keyboard. That's also weird because I've never used such a thing before. I went to the control panel and turned bluetooth off and unchecked the option for bluetooth keyboard and mice.
After rebooting the computer it was ok until today. The same problem came back this morning. This time, connecting the mouse didn't help and when I checked the settings in the control panel, they were still as they were when I changed them the previous evening.
I was finally able to start using the computer again after taking the battery out and running off the power cable.
Is this a sign the battery is bad? or is something else going on?