Windows 7 Can't uninstall or make changes to programs as Admin!

[TKR99]

I've just reinstalled Win 7 today but have still got this same problem whereby I can do almost everything else that requires Administrator privileges, except make changes to programs - it keeps just telling me I need to be an Administrator to uninstall a program, yet I'm the only person using the PC and am defo logged in as Admin? How do I get around this?

 

[TKR99]

Seems to be an intermittent problem - finally have gotten it to work but no idea why it wouldn't let me previously