Registry Writing Error

[Steve]

I can not add a key to HKEY_LOCAL_MACHINE or HKEY_USERS,
I get an "error writing to registry". I can change
values to items under these keys. I can add keys
elswhere. I tried reinstalling XP but still have the
problem. Any ideas?

 

[Kelly]

How are you trying to add it and what is the key you are trying to add?