>>17
Actually, OP here I did that while I was bored at school. On certain processors (P4 HT around 3ghz) I was able to make an exe in notepad that took up 100% of the processor.
Try it yourself:
1. Open notepad
2. Copy and paste the following line into notepad:
<M@0100`XX
3.Save as a .exe, this will tax the CPU to 100%
4.????
5.Profit!