Did a quick search for some guidance on this but couldnt find anything

. My problem is everytime i open a file, my computer searches the A drive first, and sometimes it will also search my primary and slave disk drives before it goes to C drive. This problem has only started since i installed a new motherboard (gigabyte AGP-8X) with an athlon 3Ghz 64-bit processor. I havent changed my xp install since the update??