okay.
Let me think...
Questions:
What computer is it? (Brand, Type + Model Number or Model code)
When did you get it?
When was the poor thing last disassembled for maintenance?
When last de-dusted?
Diagnostics - see if the CPU is on fire:
http://www.alcpu.com/CoreTemp/
May be 5 minutes of work only...
Here is hope for a cheap and fast resolution of the situation by letting a Tech have a look at it.