Serial code requested after every update

This should not be happening normally. NetWorx should request the licence key once, and then use it for further updates until the end of the update period included in the licence. However, there are a few situations that may lead to the issue you are experiencing:

• If you uninstall the application before installing a new version. In this case NetWorx diligently cleans up after itself and removes all its data, including the licence. If you want the key to remain and keep all the application data, you should simply close the current version and install a new version over it.
• If the older and newer versions are of different editions. For example, if the older version was installed and the new one is a portable edition, they should and will work independently, so the new version will not see any old version's data and vice versa, including the licence key. It may be worth searching the entire hard drive for networx.exe to see if you have more than one copy of NetWorx.
• If you use some Internet security or antivirus software that places every new update of NetWorx into a sandbox (environment isolated from the rest of the system). We have seen this behaviour with Comodo and several other antivirus products. If you are using a security/antivirus product, please whitelist NetWorx so it runs directly instead of a sandbox.