Just ran across this and decided to clarify
WEI (or winsat, to be precise) doesn't reset anything. It simply takes a note of the current power scheme GUID, switches to the High Performance scheme for test(s), then restores the power scheme. It's pretty clear from the log located at %WinDir%\Performance\WinSat\winsat.log.
Originally Posted by Hopachi
Here's an example from the disk speed assessment.
If the screen brightness on your PC varies depending on the power scheme, you can clearly see the change. For example. you have the brightness for Balanced at 60% and for High Perf at 90%. Run any winsat command on Balanced (e.g. winsat disk -ran -read -drive %SystemDrive:~0,1%) and the screen will change its brightness twice.
32619902 (5360) - exe\syspowertools.cpp:0983: > Read the active power scheme as 'a1841308-3541-4fab-bc81-f71556f20b4a'32619918 (5360) - exe\main.cpp:2925: > power policy saved.
32619980 (5360) - exe\syspowertools.cpp:1015: > Set the active power scheme to 8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c'
32619980 (5360) - exe\main.cpp:2946: > power policy set to maximum.
32620230 (5360) - exe\main.cpp:0868: > WinSAT info: Version=V6.2 Build-9200.16420
32620230 (5360) - exe\main.cpp:1008: > IsOfficial=TRUE IsFormal=FALSE IsMoobe=FALSE RanOverTs=FALSE RanOnbatteries=FALSE
32620230 (5360) - exe\main.cpp:4261: > Power 'execution' request successfully set.
32620230 (5360) - exe\main.cpp:1853: > Run Assessment disk -wsswap -drive C:
32620230 (5360) - storage\diskprof.cpp:0161: CCC Support not disabled in registry
32620230 (5360) - storage\diskprof.cpp:0677: DiskProfilerThreadProc Launched with priority 0
32620230 (5360) - storage\diskprof.cpp:0690: ITERATION NUMBER 1
32620230 (5360) - storage\diskprof.cpp:0698: Random seed is 1367113664
32621369 (5360) - exe\main.cpp:4300: > Power request 'execution' successfully cleared.
32621369 (5360) - exe\processresults.cpp:5288: > Wrote wsswap throughput, from the profiler, to the registry 321536
32621369 (5360) - exe\processresults.cpp:5298: > Wrote wsswap interference, from the profiler, to the registry 1114114
32621369 (5360) - exe\processresults.cpp:5375: Skipping Registry Entry for random read disk score
32621369 (5360) - exe\processwinsaterror.cpp:0340: Skipping writing the exit code, cant msg and why msg to registry
32621400 (5360) - exe\syspowertools.cpp:1015: > Set the active power scheme to a1841308-3541-4fab-bc81-f71556f20b4a'
32621400 (5360) - exe\main.cpp:2987: > Power state restored.
32621400 (5360) - exe\main.cpp:3002: > Successfully reenabled EMD.
32621400 (5360) - exe\main.cpp:5341: > exit value = 0.