Step 0: download and install the program
Most people have already installed the free trial version before purchasing, but if you don't have xplorer² just get the trial version from the download page. Make sure you install the correct edition that matches your purchase (professional or ultimate)
Step 1: start the license manager
First you must find where to put your unlock key. There are several possibilities. The easiest is when xplorer² asks for the key when you first start the program, where you just click on I have an unlock key button:
It is possible that xplorer² won't ask for the key like that (e.g. if you are in the first day of your trial). In that case, you must find a menu command called Activate with key. Where is that? It depends whether you are using the "modern" ribbon interface or a traditional menu bar. If you have the ribbon, the activate command is under the leftmost FILE tab:
small print: if you are used to the traditional menu and want to get rid of the ribbon, use Show normal menu command as seen in the above pic
If you have the classic menu-bar interface, then the activate command is under HELP menu:
Using any of these 3 routes, xplorer² will ask you to start the license manager. This is a separate program that must be run with Administrator credentials. If you are not allowed to install programs, please contact your computer administrator.
Step 2: enter your unlock key
Your unlock key is plain text and quite long. The important part is the few (3-5) consecutive lines that include your name and some funny numbers:
Your registration key is: 121|test|X2.2|1|12.03.17|0|Bob_Useremail@example.com|K98WH7BVOz zzjVW7wlYIJMd2r+frGoFPBjOncvcK2bQWc/Qc5mb1pyijEg/YsqCdNns14D 0kWQF8+5Y0= Your registration reference# is: X2.2-AFFC95D1
Obviously it is not meant to be typed but copied from your email and then pasted in the license manager window. It doesn't matter if you copy just the key or even include the parts saying "Your registration...". If you do it right, you only need to copy the text then the dialog will insert your key automatically.
Click on Activate license button to validate your key. If all goes well, xplorer² will tell you your key is fine and create the license file X2.LIC in the installation folder. It is important that your key matches the xplorer² edition (pro/ultimate) and version number (see the red highlighted areas in the pic above). Many people buy the ultimate edition but install professional (or vice-versa) — that will cause trouble (see below)
Don't worry about the activation term. It doesn't require an internet connection like other types of software
Step 3: profit (?)
Finally restart xplorer². You shouldn't see the evaluation (nag) dialog ever again when the program starts. Using Help > About menu command (or the equivalent from ribbon's FILE tab) you should see your name in the About dialog box, congratulations!
If you get this error and you decide to contact support, please take note of the exact error code as highlighted above (e.g. -2:3) and quote it in your email. There are other error messages that are more explanatory and should help you figure out what's wrong. Here are the most common problems:
A very small minority of users report a very weird problem. They go through all steps 1-3 and everything appears to work, but xplorer² still nags for a license!? I haven't managed to pin down this problem but 99% of the time it is down to an over-jealous anti-virus program not allowing xplorer² to do its validation. You can try adding xplorer² to your antivirus' trusted programs list or temporarily disable your AV to let xplorer² activate (you can disconnect from the internet to minimize the risk) — then reenable your antivirus.