Mouse and keyboard wont work

[jasonayton]

I have had my computer just over a year and over the last couple of weeks I have had some problems with it, I took it to a IT specialist and he replaced the power supply because the computer kept rebooting itself. The new power supply went bang when i first used it so replaced it with a new one which worked fine until it rebooted itself again but this time once it rebooted itself the mouse and keyboard wont work. when its first loading up caps lock, num lock and scroll lock lights flash rapidly for a couple of second but when it comes to signing into xp the mouse and keyboard wont work, however i can access setup menu's before hand by pressing F11. Having been speaking to a couple of people one said the motherboard may have been fried and the other said my windows may be curropted;. I need help !