If you tried to uninstall Microsoft Proxy 1.0 or 2.0 and the uninstall failed:

01. Delete the following folders on your disk, if they exist:

      \urlcache                                    \msp                                    \winnt\system32\msplogs                                    \inetpub\scripts\proxy
02. Delete %SystemRoot%\System32\drivers\ipfltdrv.sys, if it exists.

03. Delete the following registry keys (and sub-keys), using Regedt32.exe:

       HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3Proxy                                    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WSPSrv                                    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3Pcache                                    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\IpFilterDriver                                    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\mspadmin                                    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\mailalrt                                    HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Currentversion\Uninstall Microsoft Proxy Server                                    HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\W3Proxy
04. Delete the following value names at:
    HKEY_LOCAL_MACHINE\Software\Microsoft\MS Setup (ACME)\Table Files                                    <MSP@v2.0.372.12> - for Proxy 2.0                                    <MSP@v1.0.194.2> - for Proxy 1.0