"Instruction Memory Could not be read" Nothing Opens!

Hi Guys

I'm having a problem that seems to happen to a few people but in my case it seems more severe and I haven't found any help thus far.

I started getting a message that read "The instruction at 0x00149D04 Referencing memory at 0x0019400. The Instruction memory could not be read". The numbers obviously change depending on the program, but it appears when ever i try to open ANYTHING. Any app seems to be blocked by this! I can only use windows explorer and even then it wont alow me to go into some of the control panel options (eg: internet options).

I've read, and suspect, that this is a badly installed tool bar option, and I think it was an Adobe Reader bar that asked to install itself. I've tried safe mode and the message persists.

Any Ideas? I'm running Windows XP Pro.

Thanks guys