Reason: Internet explorer security update 'Cumulative Security Update for Internet Explorer 7 for Windows Vista (KB2586448)' was installed along with the below patches but the machine was not restarted:
Security update for Windows Vista (KB2564958)
Security update for Microsoft .NET Framework 4 on XP, Server 2003, Vista, Windows 7, Server 2008x86(KB2572078)
Security update for Windows Vista(KB2579686)
Security update for Windows Vista(KB2567053)
Security update for Microsoft .NET Framework 2.0 SP2 on Windows Vista SP2 and Windows Server 2008 SP2x86(KB2572075)
Solution: Restart PC and trying opening the document again. The above mentioned error no longer appears.
