Vista pr.exe has stopped working - have searched and no solutions

[demh23]

When I try to open PR this happens:

pr.exe has stopped working

Description:
Stopped working

Problem signature:
Problem Event Name: CLR20r3
Problem Signature 01: pr.exe
Problem Signature 02: 0.0.0.0
Problem Signature 03: 4a619738
Problem Signature 04: ProjectReality
Problem Signature 05: 1.0.3486.17244
Problem Signature 06: 4a619738
Problem Signature 07: 85
Problem Signature 08: 4
Problem Signature 09: System.MissingMethodException
OS Version: 6.0.6000.2.0.0.768.3
Locale ID: 1033

I've made sure it is targeted to the correct .exe

[clueless_noob]

That's a hairy one... Try to re-install all .Net runtime packages and then all security & recommended updates from Windows Update. If you need to reboot your computer after installs, then go back to Windows Update and check for updates. Repeat until there is no updates available.

[demh23]

Thank you very much, installing all recent Windows updates solved the problem.