If you really can not reset your windows administrator password, I recommend Windows Password Seeker, You can Google Windows Password Seeker.
I had removed Windows password with the tool successfully on my computer. You simply do as follows:
Step1, download Windows Password Seeker.
Step2. Remove your Windows Password with the tool.
If having some questions, you can read carefully at it's official website. Hope it helps!
To reset a forgotten Windows password on Acer computer, there are several free methods:
1. Reset Acer password with another admin account.
2. Reset Acer password with Windows password reset disk.
3. Reset Acer password in Safe Mode.
4. Reset Acer password with CMD.
5. Reset Acer password using "lusrmgr.msc"
More dtails you can found on other sites, it is easy to find.
Anothe tip: Recover Acer password with a Windows password recovery tool.
This method requires you to load a Windows password recovery program.
1. Install the program on another computer and create a password recovery disk with USB
2. Insert the disk to your laptop and set your laptop to boot from it.
3. All user accounts will be loaded, then you can reset any user password.
If you want to read more details: http://goo.gl/3ZNY5