finder not responding

Have you checked and eventually repaired the HD ?

This is in addition to Walter's reccomendation to do disk verify, if after the disk verify it shows errors click repair disk. If repair disk id=s grayed out, you will need your original install disks, and run disk utililites to repair. Then try out the MBP and see if it works normally. If not move on down below.

You can a system managment control reset:

http://support.apple.com/kb/HT3964

You can try a safe boot to see if it 3rd party software causing it.

Power up holding shift key (this will take longer than a normal boot, be patient) continue to hold shift kry till you se e the progress bar, then release and let iy finish booting. Try rebooting and check performance, if still no joy, do the below.

See how the MBP performs, if it is ok, then start by disabling 3rd party software, enabling one at a time till you find the offender, then get rid of it.

You by chance are not running MacKeeper are you?

Try deleting the browsers, then reloading, maybe that will help. MacKeeper is considered by many to be malware that grows worse with time.