Hi,
When I try to launch msn messenger 7.5 on my XP-Pro pc it tells me that a new version is available, if I say no to the upgrade it blocks, and if I say yes it downloads some file and then blocks with the following message:

HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\MEDIAPLAYER\UIPLUGINS\[0776F107-F5A6-404B-9A78-7027FA6EAADD]
errore 1603

I heard that the 7. version is better for XP so I downloaded it but it won't install because a newer version is on the pc.  But when I try to unisinstall the 7.5 version I get:

"impossible to open HKEY_LOCAL_MACHINE\SOFTWARE\MICROSOFT\MEDIAPLAYER\UIPLUGINS\[0776F107-F5A6-404B-9A78-7027FA6EAADD]
make sure you have sufficent rights for this key"

(sorry if not exact words I'm translating from Italian)
But I'm logged in with admin rights.

Can someone help me PLEASE, messenger and my son are driving me crazy.

Thank you

This is only a workaround.

Open Windows Media Player, from its menu, go View>Add-ons>Other, here untick Windows Live Messenger Music Add-on. Now try to uninstall it.

Or try manually deleting that key from registry. you can access Registry by Start>Run>regedit . But modifying registry is risky and manually modifying it may cause your programs or computer not to start properly or never. Do it at your own risk.

Thank you ahmetgns for your reply.  Unfortunately none will work.

1) "Open Windows Media Player, from its menu, go View>Add-ons>Other, here untick Windows Live Messenger Music Add-on. Now try to uninstall it."  Do not have this on wmp

2) When I try to delete the key from the registry I get an error saying the key can't be opened.

Will appreciate any other suggestions.  Thanks.