How to access registry through command prompt?

I deleted the "CTCGina.dll" in the registry. I'm an idiot. Can't even get into windows now. Please help!

 

I would suggest using the i386 directory from your disk and extracting MSGINA.DL_

1. Start your computer with the Windows Setup floppy disks or with the Windows CD-ROM.
2. At the 'Welcome to Setup' screen, press F10 or press R. (Windows 2000 users will need to press F10 or R and then press C).
3. You should now see a list of installations and the prompt "Which Windows Installation would you like to log on to?"
4. Select the appropriate number for the Windows installation that you want to repair.
5. Type the administrator password and press Enter. If the administrator password does not exist, just press Enter.
6. From the recovery console, issue the following command:

expand D:\i386\filename_ C:\<destination>

where filename_ signifies the name of the file you want to extract, 'D' signifies the drive letter of the source you are extracting from and<destination> specifies the path of the folder to which you wish to extract the file.
7. After the file has been extracted, type exit to leave the recovery console, remove the Windows Setup floppy or Windows CD-ROM and restart the system normally.

 

The file MsGina is still there, I deleted the filename CTCGina.dll from the winlogon registry key. Can i restore to a previous day through command prompt?

 

I figured it out, thank you. I went into safe mode and fixed it. cheers!