#1 Check if you have purchased the software correctly.  If you want to purchase the TuneFab M4V Converter for Windows, then please click to the Windows-shaped icon to get TuneFab M4V Converter for Windows downloaded and add the TuneFab M4V Converter for Windows to cart. If you have purchased the wrong version of the software, please contact us immediately and we will exchange the software for you. 

#2 Please note that one activation code can only be used on one computer. If you have already activated the software on a computer, then you won't be able to use the same code to activate the software on another computer. If you need to use the software on multiple computers, then you can buy the family license.

#3 If you come across the error codes like 901,903,905 during the activation process, please try to activate the software offline. Or you can submit a request for further assistance.