Microsoft Windows Registry Guide, Second Edition
Taking Ownership of Keys
By default, Windows assigns ownership to the HKLM and HKCU as follows:
Administrators own each subkey in HKLM.
Users own each subkey in their profile hives, HKCU.
If you have full control of a key (and administrators usually do), you can take ownership of it if you're not already the owner by following these steps:
In Regedit, click the key for which you want to take ownership.
On the Edit menu, click Permissions; then click Advanced.
On the Owner tab, select the new owner, and then click OK.