So the geniuses at Microsoft somehow decided that they don’t trust developers to be able to set their own IP Precedence or DCSP values to packets for their own applications. Fortunately, we can still override this with Windows XP (not so for Vista and beyond…). Simply do the following:
- Click Start, click Run, type regedit, and then click OK.
- In Registry Editor, locate and then click the following registry folder: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\DisableUserTOSSetting (if it doesn’t exist, create this DWORD value)
- Set the value to 0
- Reboot the computer