crackpaq sucks

You do realize that you weren't actually talking to a Compaq employee, right?

All major OEMs outsource their tech support. They're given a flow-chart and a list of questions to ask the customer... maybe even a list of specs for the computers. That's it. Unless they have actual knowledge of a PC (something that's not required to work at these support lines), they won't be able to answer any questions outside of what they've been told or what they read in their 'manuals'.

Best place to go when you have questions like that is right here. I'll tell ya right now, YES you CAN replace the Compaq stock PSU with a 400W PSU... provided that it will physically fit inside the case. In fact, you could rip everything out and replace all of it... if that was your heart's desire. You void your warranty, of course, but then if you buy retail parts... you have nothing to worry about.

Next time you have a question, ask it here. Don't bother phoning Compaq tech support, because it's likely you won't be talking to someone that actually works at Compaq.

<font color=red> If you design software that is fool-proof, only a fool will want to use it. </font color=red>