Hi everyone.
After a particularly nasty Windows 7 update, (I believe it was the SP1, althought I'm not sure) osu! stopped working for me and both it and osume would crash upon starting.

This was just like the problem benatkins2007 had about a year ago.
And just like him, no matter if I unstalled or repaired osu! or .NET framework, the problem just wouldn't go away.
The solution I found (from digging through here) was to put a copy of the 'System.comfiguration.dll' located in 'C:\Windows\Microsoft.NET\Framework\v2.0.50727' in the osu! folder. After that, it worked just fine again.
TL;DR: Copy 'System.configuration.dll' from '%windir%\Microsoft.NET\Framework\v2.0.50727' into osu! folder.
After a particularly nasty Windows 7 update, (I believe it was the SP1, althought I'm not sure) osu! stopped working for me and both it and osume would crash upon starting.
This was just like the problem benatkins2007 had about a year ago.
And just like him, no matter if I unstalled or repaired osu! or .NET framework, the problem just wouldn't go away.
The solution I found (from digging through here) was to put a copy of the 'System.comfiguration.dll' located in 'C:\Windows\Microsoft.NET\Framework\v2.0.50727' in the osu! folder. After that, it worked just fine again.
TL;DR: Copy 'System.configuration.dll' from '%windir%\Microsoft.NET\Framework\v2.0.50727' into osu! folder.