Admin Account Corrupted

I have Vista Home Premium 32bit with SP2 and all the latest updates.

I have two accounts set up; 1 admin account and 1 standard user for daily use. Recently, the Admin account would not let me change file or folder names and many of my own folders were marked as read-only. Even taking ownership of the folders did not solve the problem. Also, programs like FireFox would not run from that account at all.

Many have suggested online that a registry cleaner removed a registry entry. I never use registry cleaners, they are a really bad idea.

I created a new admin account and everything is working fine on that account.

For future reference so that I can avoid this problem: What causes might there be for losing read/write ability and the ability to change file/folder names?

There can be many different reasons for this, was the files concerned in an external drive?
Have you had any updates that have failed?

There are many tutorials on these symptoms here;

http://www.vistax64.com/tutorials/?filter[11]=File%20Folder%20Settings

Yeah, the standard things you would think of don't seem to apply. No external drive, no network share, no new installs, no new updates, no ungraceful shutdowns.

Thanks for the link. I will go read up on it and try to prevent further problems.