Hello and welcome to Tom's Hardware Forums.
The Registry is a crucial part of a Windows system and not a place to take risks in. You get there by going from Start to Run then into the Open box, you type regedit then press Enter. Before you do anything else, select Export from the File menu then note the name and location of the backup file you're about to create because you might be glad you did if anything goes wrong.
All that said, what's the problem and why do you think going into that hive will help?