I have a problem with my old computer. I want to be able to boot windows 7 from a sata drive. It has a sata controller on the motherboard, but there are no drivers to be found for windows 7.
The P5Q-E has two SATA controllers, the ICH10R (red SATA ports) and the Silicon Image SIL5723 (two SATA ports orange/white). providing you are attaching the drive to one of the ICH10R SATA ports, there should be no issues booting into windows. You will need a driver to boot from the Silicon Image controller.
If you are not referring to the P5Q-E, then list the make and model of the specific motherboard you are trying to use.
I remember reading somewhere it's not possible to boot from a drive on a pci controller expansion card...is this true ?
No, this is not true. Briefly, as long as the controller card is recognized in the BIOS, and the drives attached to the controller are recognized by the controller, then using the controller BIOS you can configure the drive array (RAID, JBOD, etc) and then set the boot order. Of course, using a controller card you will need to hit F6 to install the controller card drivers in order to load windows onto it.
There are also 2 sata controllers on board. From one of them I don't seem to be able to boot(not recognized by the bios I guess) and for the other one there are no drivers to be found for windows 7.
The two SATA controllers onboard the A8V Deluxe are the VIA VT8237, which the is southbridge part of the VIA chipset, and the other is the Promise Fastrack 378 (Promise PDC20378) SATA/IDE RAID controller, which is an additional controller providing the 2 additional SATA ports and two addition IDE channels. Depending on which SATA port you connect the drive, and subsequently which controller you are connecting to, doesn't really matter because they are both not natively recognized by Windows7 and you will need to download the drivers for Windows7 for each controller. Thankfully, with a few minutes and a google search you can find places to dl the drivers for each controller.