Iam installing a new hard drive and once I installed it it went into dos asking for a command for C:\ I dont know what that command is or what to do is there anyone that who can help me please thank you.
1) What OS did your computer boot to before you installed the new hard drive?
2) Is it brand new, or did you get it used?
My best guess is that the new drive had DOS installed for some reason, and when you installed it you attached it to a lower-numbered controller port, so the system is booting from it. Try fiddling with the BIOS (if you know how) to make your old drive the boot drive.
Simple test: Remove the new drive. If the system boots normally, what I wrote above is 98% likely. If the system still boots to DOS, take the DOS floppy out of your floppy drive. If you don't have a floppy drive, you have an interesting problem.