Need Some Help Please

Could anyone help me with this please? My relatively recent PC has developed a strange issue. When I start the computer it begins to load and it seems to load fine but after perhaps 20 seconds it freezes up. It won't Ctrl-Alt-Del and the only thing I can do it pull out the power cord and start again. Restarting and immediately running a virus scan seems to resolve the problem, even when the scan finds nothing (nearly always). But after shutdown the same thing occurs. I thought there was soemthing wrong with the startup but it seems ok. I have Spy Sweeper and Kaspersky. Can anyone suggest the steps I might take Thanks

Hi Spiny Norman, When your PC is starting up, Tap F8 to get into safe mode. You'll need spybot, whether you downloaded it when you're on your normal account or it's on a USB pen…Then i suggest you have your USB pen ready, or run Spybot if you've already downloaded it, make sure you've nstalled the latest updates and then run the program, hopefully it'll run ok in safe mode. It may find some things that is causing the problem. Once it has finished, select what it has found and remove them. Restart the PC and let me know the results. 'Bob

Hi Spiny Norman, Looks to me that you will be dragging that machine over to the Malware Removal Forum. You've been there before, so you know the drill. Best Regards