Windows XP Won't Powerdown

This problem seemed to start after I installed a cracked Altbinz .30. The program just wouldn't download anything correctly. So I posted on the Altbinz website and they told me the cracked version has a Trojan virus attached. I then got rid of it and installed the version I was using previously to a different directory and files within that program downloaded perfectly. Later that night when I shutdown my windows XP Pro SP2 OS, it wouldn't complete the full power down. My monitor will go to standby mode as it usually would but my Tower stays on (One of the lights on my CD Drives stays on and doesn't shut off, the power and Hard Drive lights stay constant). It won't shut off even if I hold down the power button. The only way I can shut off the PC is by switching the off switch on my Power Supply. When I try to put my computer on after wards by switching the Power Supply back on, the computer remains at that same position as it was when I tried to power it down. But this time when I hit the power button it restarts the computer. This problem continues to persist. I researched this problem online and tried many suggestions. I ran an anti-virus, Zero day and Spy-ware scanner. Next I went into Safe mode and deleted the altbinz exe that .30 had created. The computer still wouldn't power down. I used the ShutNTDown Registry patch and added a powershutdown setting in my registry manually as I read online, both with no result. Then I tried running Windows File Protection (sfc /scannow) and it found nothing. I ran HijackThis and didn't see any abnormal problems. Then I tried reverting to an older system restore which my computer failed to complete. I updated to the latest bios and cleaned the inside of my tower with an air can. I looked for the power options in my computer and can't find it. I then enabled ACPI in my bios because I don't have APM and then looked and the power option still wasn't available. Then I tried restarting in safe mode and tried shutting down and it still wouldn't power down. Then I tried reverting to the last known good configuration with no positive result. I really don't want to have to reinstall my windows, but this seems like the last step before I determine that it is a hardware problem. Can anyone else tell me what I can do to fix this problem? Any help would be greatly appreciated. I did all the cleans suggested on this website. The computer shutdown perfectly, however in the middle of the night the computer started itself up. I ran Symantec Antivirus, Counterspy and Stopzilla in safe mode. After it fixed the extra spys it found, when I rebooted into windows, my internet went down. My ISP could not fix it. I then did a repair of my copy of Windows XP, I still couldn't connect to the internet. Ran a winsockfix, called my ISP and they fixed it. However my computer STILL won't powerdown. My tech at the ISP told me it sounds like I have a Stealth Spyware Script and that only Spy Sweeper will fix it other then a complete format and clean windows install. Are there any steps to do now without having to format and do a clean install or determine it's a hardware problem?