Win7 only would not REstart, gets stuck at BIOS start?

[burgul]

I have a PC that won't restart from windows 7, but would shut down perfectly fine.
It would also restart fine from XP or by using the physical reset button (automatically starting Win7). And it would power on fine.
It's a new install of Win7 on a new hdd in this computer, so I can't compare it with the past. Mother board is MSI P4M900M.
What happens with Win7 is, it would begin restart – shut down, make the power switch tick, followed by movement sound from the CDROM, and then a black screen & fans all spinning. Nothing else. Ctrl-alt-del won't work then – only the physical reset button. These sounds that it makes are exactly like the 3-4 first seconds after pressing the physical rest button, but then it stops.
Voltages from the bios and from the molex connectors look fine. CPU, memory, HDD tests are all fine.
There's no bios update and reflushing, clearing cmos didn't help.
I tried disabling the cdrom and disconnecting it, disconnecting the old hdd, disabling legacy USB support, disabling serial and parallel ports, changing case fans, changing molex used – all with no change.
Wake on PME is enabled, disabling it only makes things worse, not being able to power on in many attempts.

Any idea how this would happen only from Win7, but after already restarting?

Thanks in advance for any help/idea!

 

[burgul]

Since the display doesn't turn on, I thought maybe it has something to do with the integrated graphics adapter, so I tried the most basic display settings and installing the driver from VIA (rather than by Microsoft), but no change.
Searching online I saw someone commenting that lowering the refresh rate helped with something of that kind, but I couldn't find a way to change that or to even see the rate. The PC is connected to a LCD display, and I can only choose default refresh rate, no number.

Any thoughts?