I did not change any settings in Windows. I am using SPFPRO on XP Home with SP3. I used to get 100% CPU usage when I was using the swap, FSPLIT, VSPLIT commands or a PFKey to swap between files. Now that I am not, It never locks up though I am using it for five or six hours at a time. Are you by chance using it on and AMD processor?
I have also used SPFPRO on Vista and Windows 7 with no problems from a USB flash drive. Again, the CPU stays normal so long as I edit only one file at a time and never use swap, fsplit, vsplit or any pfkey to swap between files.
I have used SPFSE and have found the Standard version most like what I am used to with SPFPRO. I have been able to get most of my REXX (.SPF) macros to work with it. Only Problem I have with SPFSE is that it is windows install dependant meaning you need to install it on each machine. I often use it on several virual machines and don't want to install it each time I need to use it. I have asked the author to look into making it independant of user account install. Hopefully he will be able to do so in a new update.