Runtime Error

I've had my video iPod for 3 weeks, no problems. Yesterday I tried to load a new CD onto iTunes and get the following error message:

Microsoft Visual C++ Runtime Library
Runtime error c:\program files\itunes\itunes.exe
Application required runtime to terminate in an unusual way
Contact your blah blah blah for help

Please note I am as far from being a PC expert as can be, so please be very detailed (and gentle) in your replies.

Thank you.