Tampered with the registry and now I cannot log-on

Basically I deleted what I thought to be a virus from within the registry. The path I took was HKEY_LOCAL_MACHINE > SOFTWARE > Wow6432Node. Wow6432Node is the directory I deleted. I then noticed that I couldn't run any programs on my desktop as a error message would appear (I can't remember what it said). I then decided to restart my computer to see if that would fix the problem. When I was back at the Welcome Screen, there were no user accounts that I could log on to. I then took the hard drive and connect it to my brother's computer whilst his working hard drive was still connected. I then enabled the built in administrator account and was able to open my hard-drive as that user. I can access all of my files but only when logged in as the administrator and on my brothers computer, using his hard drive to start up. Could someone please explain step by step what I should do to get sort this out? I imagine I'd have to reset the registry of my hard drive by using my brothers computer. Could someone please explain ad to do this? I'm obviously not good with computer or else I wouldn't be in this situation, so I'm going to need you to dumb it down for me. Thank you

Will that wipe my files? And will I have to have made a back up of my hard drive before hand in order to do this?

See this tutorial by Brink, and do Step 10 to Show affected programs and drivers:
System Restore

Thank you to everyone for your help, I'll give you all positive rep when I get this working. And I'll take your advice of not tampering in future

I cannot do a system restore as I don't have a GUI for my hard drive, I only have the files. However, I have a GUI for my brother's hard drive so it there anyway I could open up the registry and change it from his hard drive to my hard drive and then reset it to default settings from there?

If System Restore will not complete when you access System Recovery Options
via F8 or disk, then try accessing the Command Line to Enable Built-in Administrator from WinRE - Windows 7 Forums.

If this will allow you to boot, create a new Admin level account to move your files into, make sure all programs run correctly. Then disable Hidden Account.

You can also try restoring the registry backup to see if that will help following the same procedure as for Startup Repair Infinite Loop Recovery - Windows 7 Forums.

Make sure System Protection is enabled again for C with plenty of disk space apportioned. Keep a System Image backup for cases like this.