Hi Jon. The following thread seems to be the identical problem. Perhaps it will give some pointers:

New XP workstations experience slow data access Thread #749089 Message #749089


>I am curious if anyone would have any insight as to why performance on our VFP7 application would decrease dramatically when the workstations are upgraded from NT4 to XP. Here are the details:
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>The server has been Win2000 SP3 for some time, so the server is not the issue. Anti-virus has been disabled completely so we know that is not the issue either. When only one XP user is logged in to our app, the performance is faster than it was under NT4. However, when additional users log in then the performance goes way down below the multi-user access benchmark that was achieved with NT4 workstations.
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>This is sounding very much like there is some sort of issue or configuration item under XP that needs to be addressed.
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>Could someone offer any ideas?
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>Laterness,
>Jon