[Grzyb]

I have 2 500w PSU's hooked up together to Power all the Gear I have in my main Rig....

7 Hdd's
DVD Rewriter
CD Rewriter
CD Rom Drive

And all the other assorted things that you need, all housed in a LI-LAN Case.....

All working smooth & steady.....

400w for your setup does seem too low....

For your other problem, goto the minimal setup config....

One Hard Disk. Video Card, Memory & CD Rom and try that...