|OK, then it sounds like the bios takes a short time to detect the wireless keyboard's USB receiver / transmitter while booting, but it does detect it / the wireless keyboard after that. |
I downloaded the manual for your P5Q Deluxe and looked at it.
As I expected, there is absolutely no mention of bluetooth in it. There is also no mention of wireless keyboards or wireless mice in it, but it does mention things about wireless network adapters.
By the way, most if not all wireless keyboards and mice use bluetooth - they typically have a range of up to 30 feet max or so, which is the limit for bluetooth - if they used e.g. wireless G, you could use a wireless keyboard or mouse a lot farther away from the transmitter / receiver.
"....my P5Q Motherboard doesn't let me use the Flash OS..."
What are you referring to?
It's NOT a good idea to attempt to flash the bios unless you MUST. Flashing the bios is the riskiest thing you can do with a computer ! Bios flash chips can only flashed a small number of times - sometimes the flash chip fails physically the FIRST time you attempt to flash the bios - if the flash chip fails physically, your computer will never boot again after that until the flash chip has been replaced - on many mboards these days the flash chip is soldered into the mboard and can only be replaced by an expert - it's often cheaper to replace the mboard. .
There is nothing mentioned in the release notes for the bios updates for this mboard that mention anything to do with bluetooth or wireless anything.
The manual was made in 2008, so the bios supports booting from bootable USB drives, if the settings in Boot are correct for that, if that applies (they may be recognized automatically regardless of the Boot settings) .
However, if there is a Windows operating system on the USB drive that is 2000 or later, you get a blue screen 0X0000007B error = INACCESSIBLE_BOOT_DEVICE when you try to boot from it - it's difficult to get around that problem - Microsoft doesn't want you to be booting from removable drives that have 2000 or later on them.
The manual says you can't flash the bios using an update on a USB drive in any case unless you're using Vista (or, probably, Windows 7).