I run Windows 7 (32 bit) OS on a notebook with Quad i7 processors. Each time my scheduled antivirus software starts a scan, it works out the number of available processors and creates that many threads in order to speed up the scan. The processors are thus pretty busy during this time. So if I try to do any "work" whilst the scan is running, the notebook runs extremely slowly. Just starting up Word or Outlook takes an age. It is as though the scheduler is reluctant to relinquish control to another process of equal priority. This effect is only seen on Windows 7. I have other laptops and desk tops all runningWindows XP on multiple CP systems. Using the same antivirus software does not exhibit the same slow-down problems. I know that I can set the maximum number of processors for a given task, but I can only do that on a running task. The A/V software is automatically scheduled and by the time it has started, all four processors are already assigned. Is this a bug in the scheduler or is there some other way I can stay working during a scheduled A/V scan? Many thanks for any suggestions.

I don't know if I would call it a bug or weak programming. Doesn't seem like it's really a Windows 7 product. How it performs on other OS's really doesn't matter. You need a Windows 7 product. You should have no issues like that with that hardware. You could check that Windows defender real-time protection is disabled. Click Start=>type defender=> select it from the results=>select tools=>select options=>uncheck the real-time protection box=>select ok. Perhaps there is a conflict. Multiple real-times cause problems. Or...You need to change your anti-malware application to one that uses little resources. From the list here- http://www.microsoft.com/windows/antivirus-partners/windows-7.aspx, Eset, Avira and Microsoft Security Essentials are effective and very light on resource usage. I have tested all except four. Some you don't even want to install.

Thanks for your reply. I had thought it might be a problem with the (non-windows) software - but if so, it seems to be prolific. I gave the A/V software as an example - because it is one piece of software that is scheduled to start at a particular time. I have noticed this problem with other software (admittedly also non-windows) as well. Surely you are not saying that as Windows 7 is "so new" there has to be a complete change in all software that purports to run on a Windows platform? If that is the case, then I would definitely question the underlying continuity of successive Windows releases. Thanks again for your reply.