>I have VFP5 installed on my pc. Can I install VFP6 on the same machine without problems?

You can have both products on the machine with no problems as far as the programs themselves. You may run into problems with some of your default file associations, especially if you've customized them in the registry; for example, having both versions on the system will assign the VersionIndependentProgID VisualFoxpro.Application, and the last product registered will be the one getting started by default. This can mean tht you'll lose access to some of your customization, since it might be associated with the other version, whith sometimes confusing consequences (ie I created an Edit association for .PRGs under VFP5; when I installed VFP6 as well, the default for handling .PRGs when I clicked on them was the new VisualFoxPro.Application.6, which didn't have the customization entries. It was easy enough to fix by exporting the VisualFoxPro.Application.5 registry keys in a .REG file, editing the .REG file to start VFP6 and change the base registry key, and then just apply the .REG to get them back.)

I would make sure that regardless of which goes on first, I'd install the VS SP3 last, to make sure that if the installers were playing a little fast and loose, the latest version of shared components found their way onto the system.

>Will I can run and develop with both versions?
>

I do, under both Win98 and NT 4.0