How do I fix an “Invalid license data. Reinstall is required.” error in Visual C# 2010 Express?

Question

I\'ve tried to install Visual C# 2010 Express edition onto my PC, but whenever I try to run it, I get a error message.

Invalid license data. Reinstall

Answer 1

Background: Visual Studio 2012 Pro installed by Administrator account. As "Joe User" (member of Win 7 Users group, but NOT Adminstrators) I got the error message. On reading this forum I concluded this is a generic error message. Steps to fix: As an adminstrator, open HK_CLASSES_ROOT. Open context menu on the Licenses subkey Select Permissions... Set Full Control for all users.

Now log on as "Joe" again. Voila!

Next, as Administrator change the permission on HKCR/Licenses back to read only for Users.

Two hints for developers. If you can develop and run an application as an ordinary user, then presumably your poor clients don't need admin rights to run it either.

Don't leak security information in "helpful" error messages. Microsloth are probably following their own advise and giving a vague and unhelpful error message here.

I have no idea why changing the permission to FC then back again to the original setting worked. I can only assume the Visual Studio writes something to that key the first time it runs.