I am running windows 7 on two machines and both crash (blue screen of death) mentioning ndiswan.sys. Both previously ranVista without problems.Any advise would be appreciated.

ndiswan.sys is a windows network driver and may either be corrupt, incompatible with Windows 7, or may be a virus masquerading as ndiswan.sys. Did you upgrade install or did you do a clean wipe and install? I've found there are a great many more issues if you do an upgrade install instead of a clean fresh install. Windows 7 remarkably has drivers for most every kind of hardware except for anything really cutting edge, so driver concerns are pretty minimal.

I've heard of other Kaspersky related issues, like Windows Explorer behaving very slowly. I'd uninstall it and see what you get.