e-machine on xp will not post

I have an e-machine computer on windows xp. It has been running fine all along... no problems at all. This weekend I decided to move the computer, so I shut it down, and unplugged everything. The computer stayed unplugged until this morning. I plugged it in and connected everything again... the monitor is VGA, the keyboard is wireless with a module plugged into the computer and the mouse is usb Now, the computer does not even pass the post... it stays on the e Machine logo. There is no keyboard function and I cannot get into the BIOS I have shut if off several times and retried. I also let it sit at the e Machine logo for about 10 minutes, thinking that it might just be frozen up. I really need some help with this. Thank you