I'm trying to install windows messenger 5.1 on a vista machine to get the sip settings as we use WM 5.1 within the environtment to communicate. But when ever I try to install WM 5.1 it brings up a 0x80070003 error. I'm interested to see whether there are other people who have used WM 5.1 on vista?Regards,Chris

Hi Chris, Please understand Windows Messenger 5.1 is supported by the following Operating Systems: Windows 2000 Service Pack 4; Windows Server 2003; Windows Server 2003 Service Pack 1; Windows XP 64-bit; Windows XP Service Pack 1; Windows XP Service Pack 2; Windows XP Tablet PC Edition. Thus, we cannot guarantee the Windows Messenger 5.1 works properly in Windows Vista. For more information about Windows Messenger 5.1, please refer to: Windows Messenger 5.1 http://www.microsoft.com/downloads/details.aspx?FamilyID=a8d9eb73-5f8c-4b9a-940f-9157a3b3d774&displaylang=en Meanwhile, please choose the version supported by Windows Vista, such as Windows Live Messenger: http://download.live.com/?sku=messenger Hope it helps. Nicholas Li - MSFT Nicholas Li - MSFT

A solution or a workaround for this problem is to install a virtual machine running WinXP with the 5.1 Messenger. When connecting over VPN to your company, you do this via the virtual machine. Concerning virtual machines, you can download VMware for free. Googled it found a few posts saying disabling UAC lets it install itbut i don't know if it works or not but its worth a try.

Vista - Messenger 5.1 SIP - workaround: 1) Setup windows messenger 5.1.0.639 (SIP protocol).2) Download riched20.dll (version 5.0.150.0) from, for instance:http://www.dll-files.com/dllindex/dll-files.shtml?riched20[/url3) Copy riched20.dll to messenger folder application.