classic theme; programs dont work; ccc & desktop dont work; slower than usual; etc.

help.

when i logged on to my windows account:
vista reverted to classic theme;
i cant access my documents, My computer, the control panel. i cant go on windows explorer or access any files whatsoever;
there was an error message that said: 'catalyst control center: host application has stopped working.' ;
also there was an error message that 'C:\Windows\System32\config\systemprofile\Desktop refers to a location that is unavailable' (or similar);
google chrome doesnt work: google chrome cannot read or write in its data directory.;
opera doesnt work:" Startup Error:Opera has failed to access or upgrade your profile. This may have occurred because your computer has insufficient resources available or because some files are locked by other applications. You may have to restart your computer before Opera will start again.";
the same thing happens with many other programs.;
i cant seem to do anything that requires admin privileges (i am on an admin account but not the root admin): for example when i click show processes for all users(in the task manager) it doesnt do anything.;
the computer is about slower than usual(logging on took a long time, start menu freezes up a bit, search doesn't work);
to me it seems like a number of files and folders where moved or deleted (like in program files or something).
could this be a virus, or just a buggy or incompatible software(I just installed Miro)?
please help.

thanks

Re: classic theme; programs dont work; ccc & desktop dont work; slower than usual; et

Can you boot your computer in safe mode and access your documents, computer, and control panel?