Okay, this is driving me nuts!

My computer keeps giving me this message and is acting pretty weird lately.

Anyone know what this means? Here is what it says:

Application Error

Exception EAccessViolation in module STOOLBAR.DLL at 000076B0.
Access violation at address 122E7BC4 in module 'STOOLBAR.DLL'. Read if address FFFFFFFF.

Any help would be greatly appreciated. I don't want to use a sledgehammer!!