Most versions of 7.0 allow offline activation. When the internet activation fails, click "Manual Activation" or "Phone Activation." It will generate a code. You can often find a third-party keygen (key generator) specifically for Version 7.0 that converts that code into an offline activation certificate. Proceed with caution; only run such tools in a sandbox or an old Windows 7 virtual machine.
If your key is being rejected as "invalid," consider these common fixes: product key for honestech vhs to dvd 70