Yes the Tech Guy could get into it.
If the Admin account is disabled he can do the following.
Entering the below command through CMD will activate the hidden Admin Account.
He can do this in a few different ways.
Either Gaining accessing through an admin account or enabling it below.
net user administrator /active:yes
If he wanted to he could even do this command.
Say the USER is Foo. and the password you want to change it to is mypassword
net user foo mypassword
Also just pulling the Hard Disk out and placing it into another pc will reveal all files and directories.
For Informational Purpose of how this could be achieved with no Admin Rights.
Start your PC off the (Disk|USB|HDD) that contains the install media
Once loaded, press Shift+F10. This will open a command prompt
Run the following commands in order:
Once you find the right volume (your C: drive (it may have a different drive letter)), run exit
D is your drive letter.
ren Utilman.exe Utilman_old.exe
copy cmd.exe Utilman.exe
Once you get to the logon screen, click the
Accessibility Options icon. Once the Command Prompt opens, run these commands, replacing
user_to_change with the user you want to reset the password of:
net user user_to_change *
Enter a new password, enter it again (you won't see it) and log in.
You can now go back to
C:\Windows\System32 and delete the
Utilman.exe that we made, and rename
If you have any sensitive data and you are worried about the Tech guy getting into it pull the data off.