There have been some questions in the VFP community about what issues there are with Visual FoxPro applications under Windows XP SP2. At this time, we're still testing but we do know some basic information. Basically, the vast majority of applications will be unaffected. I'll be adding to this thread if other issues crop up.
First off, you should read http://msdn.microsoft.com/security/productinfo/XPSP2/introduction.aspx and then http://www.microsoft.com/technet/prodtechnol/winxppro/maintain/winxpsp2.mspx to get a grasp of what SP2 does.
Here's what we know so far.....
There's a switch in SP2 called the NX (No Execute) switch. It is set for the system as a whole but can be set per process. When on, it limits access to areas of memory allocated as data by throwing an access violation.
Two types of uses of VFP are affected when this switch is on:
1. Calling a COM server via early binding.
2. Implementing an interface that will be called via early binding.
Now, this switch is only supported on the AMD K8 64-bit processor at this time; NX cannot be switched on for Intel processors. Therefore, there should be no effect on VFP EXEs and DLLs on Intel machines.
I'll update this blog with code samples and any other pertinent information as it becomes known. For now, I'd summarize with the phrase “don't worry - be happy“