Hey Musiclover99,
Thanks for the question. I understand you are experiencing some performance issues with your MacBook Pro. I’d like to ask you a few questions to see if we can isolate this issue further.
First, it sounds like you are trying to record your screen. Do you have a lot of applications running while attempting to record your screen, or an application that requires a lot of memory? Does the issue persist if you attempt to screen record something else?
You can use the steps in these resources to help isolate the issue:
OS X Mountain Lion: If graphics-intensive tasks slow down your computer
http://support.apple.com/kb/PH10900
Isolating issues in Mac OS X
http://support.apple.com/kb/TS1388
Mac OS X: How to troubleshoot a software issue
http://support.apple.com/kb/HT1199
Thanks,
Matt M.