Resetting the Registry and the File Permissions

Using SubInACL

For Windows XP Home Edition (and Professional Edition), you may use the SubInACL tool to reset the registry and file permissions. Download and then install the Subinacl.exe (~370 KB) from Microsoft. SubInACL is a command-line tool that enables administrators to obtain security information about files, registry keys, etc.
Download reset.zip, unzip and run the reset.cmd file. This script resets the registry and file permissions in your system.

The file reset.cmd contains the following lines:
cd /d “%ProgramFiles%\Windows Resource Kits\Tools”
subinacl /subkeyreg HKEY_LOCAL_MACHINE /grant=administrators=f /grant=system=f
subinacl /subkeyreg HKEY_CURRENT_USER /grant=administrators=f /grant=system=f
subinacl /subkeyreg HKEY_CLASSES_ROOT /grant=administrators=f /grant=system=f
subinacl /subdirectories %SystemDrive%\ /grant=administrators=f /grant=system=f