Just like my previous post, a customer showed me how slow it was to open quotes in V6 on their new Windows 7 machine.
I fired up Process Monitor and looked at the output while loading a quote. I noticed many requests to read\write to the file V6. ini. This file resides in C:\Windows (only in V6 2.1 and older). Since Windows Vista any attempt by an application (without a manifest) to write to C:\Windows will virtualise the file to a location in the user’s profile. This is completely transparent to the application.
For some reason the virtualisation of V6.ini was causing major slowdown in V6. To stop the virtualisation I assigned the write permission to the copy in C:\Windows. This resolved the problem.