·  DWM on Longhorn 5048 revealed

DWM without a glitch or lag

   1. Open the Registry Editor (Start > Run > Type "regedit")
   2. Navigate to HKEY_LOCAL_MACHINE/Software/Microsoft
   3. Create a new key, DWM
   4. Go to HKLM/Software/Microsoft/DWM
   5. Create the following 4 DWORDs:
          * EnableMachineCheck,
          * Glass,
          * Metal and
          * UseAlternateButtons. 
   6. Set all of them to 0. (Or you can switch UseAlternateButtons to 1 if you wish to see DWM with square buttons, as this has no performance impact)
   7. Use the command rundll32 uDWM.dll,DwmClientStartup (Start > Run) to start DWM.
   8. Open your services manager (Start > Run > Type "services.msc"). Search for the service User Experience Session Management Service (UxSS) and set it to "automatic".
   9. Reboot your machine. 

You now have Aero Glass working on nearly any graphics card !

Note: Setting these keys not only make DWM quick but also disables some effects, for example the minimizing/maximizing/alt+tab effects, but there is REALLY NO LAG WHEN YOU USE THESE KEYS !

DWM with full effects enabled (but probably some lagging)
If you wish to disable the speed-up (to recover the lost effects), simply set the DWORD Glass to 1.

How this works

    * Setting EnableMachineCheck to 0 bypasses the system test on DWM startup, allowing you to start DWM on any computer.
    * When setting Glass to 0, it switches from Aero Glass to Aero. This would yield the Metal interface, but this is the point where the DWORD Metal comes in..
    * Setting Metal to 0 forces the Glass windows even when the default would be Metal. And, using the rundll32 method, DWM doesn't crash immediately like when using the UxSS method. 

To stop DWM started in this way, shut down rundll32.exe with Task Manager.
Beware! There may be multiple rundll32.exe's in the list, so enable the column "Command Line" in Task Manager, and shut down the one which has the command line of "rundll32 udwm.dll,DwmClientStartup". Now, DWM is closed, and you are back at the "basic" Aero UI of 5048.

Recommended
We recommend you use the UxSS service (set to "automatic") with EnableMachineCheck set to 0, or pass 2 arguments to DwmClientStartup (ordinal 100) of uDWM.dll.

Example: rundll32.exe uDWM.dll,DwmClientStartup 1,0