Save the installer
Open the download link from your order email and save the file. Image Tagger is ATagger.Setup.exe (about 84 MB); Video Tagger is ATagger.Video.Setup.exe (about 126 MB). They are separate apps — install whichever you bought.
Click through SmartScreen
When you run the installer, Microsoft Defender SmartScreen will most likely show a blue panel saying "Windows protected your PC", with only a Don't run button visible.
This is not a virus warning. SmartScreen shows it for any Windows installer that has not been signed with a certificate, or that it has not yet seen downloaded enough times to trust. ATagger is distributed directly rather than through a store, so it has no such reputation to draw on.
Run the setup wizard
The default install location is fine. Click Install and it finishes in a few seconds, then adds ATagger to your Start menu.
Add your two keys
Open ATagger from the Start menu. Paste your xAI API key at the top and click Save — this is the key you create at console.x.ai, and it is what pays for the tagging.
Then paste your licence key and click Activate. Image Tagger keys begin ATAG-, Video Tagger keys begin AVTG-.
If Windows still blocks it
Some setups are stricter than others. If the file disappears after downloading, check your browser's downloads list for a "keep" or "restore" option — browsers sometimes discard unsigned installers before Windows ever sees them.
If your workplace manages the machine, an administrator policy may block unsigned installers entirely, and no amount of clicking will get past it. That is a decision made by whoever administers the device, not something ATagger can change.