SM won't register in Windows 'open with' list

[playtime]

I've recently reinstalled SM Player as a complete package with MPlayer to overcome an Internet bug that stopped videos playing.

Now Windows XP has decided to adopt WM Player as first choice player when click-opening any video-type file. When I right-click a video-file from within its folder page, and select 'Open with', the new SM Player is not listed by Windows. And when I choose 'Select program', then 'Browse' and select the new smplayer.exe file, this .exe file still doesn't show up in the Windows right-click list.

SM Player plays files OK if they are selected from the player's file menu. But otherwise I can't select SM as the player.

N.B. I still have my previous version of SM installed as not sure what to delete given the integration with MPlayer. This previous version does show up in Windows right-click choices as sm_portable. But, thanks to the bug previously mentioned, sm_portable no longer works. Also, I have given full permissions to the new smplayer.exe in McAfee and removed permissions from the old sm_portable. But still not able to select smplayer.exe via Windows.

Help please?