Overclocking a CPU required switching jumpers and overclocking a graphics card sometimes required soldering an extra resistor onto the board. Windows was still extremely unsecured and writing a bit of clever assembler, you could change things in memory. My one ASM application had a bug in it and corrupted the screen memory and randomly made the internal speaker go beeeeep - i left it running on a lab computer and some students freaked out when the computer effectively did random stuff.