Remove the Windows XP administrator password

Today, I went to a company's office machine. Several machines were moved from the headquarters. They were all in one domain. The office has not used domain management. So give them both to quit the domain and reinstall the Norton Enterprise client (originally accepting server management, now changed to not accept management).
One of the computers, installed WinXP Simplified Chinese Professional Edition, after exiting the domain, did not expect the system administrator to set a password, colleagues said he did not set up, asked the installed company also said no
Most of the machines equipped by the company do not have a CD-ROM drive. The floppy drive is a rare thing. This machine is also soft and soft. The method of changing the password with the tool software is not feasible.
Fortunately, there are several machines with Win2000/XP available. Remove the hard disk of this machine and install it on another machine. Then use the following method:
Copy the \\WINDOWS\ epair\\sam file to \\WINDOWS\\system32\\config\\ directory overwrite the original file (if you are not assured, you can back up the original SAM file)
The password of the Administrator account is empty