1) If the Downloader fails to launch, try restarting your computer. If it stopped working after installing Adobe AIR 2, you will have to uninstall and reinstall the Downloader.
2) If you're unable to log in or are getting the "The application is offline or it can't contact gog.com servers" error, check or disable your firewall/anti-virus software to make sure it doesn't interfere with the Downloader.
3) If the Downloader is having problems writing to the destination folder, launch it by right-clicking its shortcut and selecting "Run as Administrator".
4) (Windows 7 only) If your Downloader alternates between "Initializing" and "Paused" modes, try changing its compatibility mode to Windows Vista and launch it by right-clicking its shortcut and selecting "Run as Administrator".
5) If you're experiencing problems with the Downloader's user interface (for instance, all you see is an empty window or if an empty popup covers most of the functional area underneath), try downloading and installing AIR2 (you may have to reinstall the Downloader afterwards). It can be found here.
If that doesn't help, try deleting the AdobeAIRELS and com.gog.downloader.***** folder(s) located inside this folder:
for Windows XP - C:Documents and Settings[USERNAME]Application Data ,
for Windows Vista and 7 - C:Users[USERNAME]AppDataRoaming .
If you're unable to locate these folders, you may have to enable displaying hidden and system files. You can find the appropriate settings by opening any folder and selecting Tools -> Folder Options... -> View tab. On Windows Vista and 7 you may need to press Alt in order to display the folder window's toolbar.
6) If you're having any other problems, please try to reinstall the Downloader completely:
- Uninstall GOG Downloader and Adobe Air,
- Delete all remaining Adobe Air directories (the locations are the same as in point 5),
- Use regedit to delete all entries containing "AdobeAir" and "Adobe Air" (WARNING: this step is inadvisable for users who aren't familiar with editing their registry),
- Restart your computer and reinstall Adobe Air and the GOG Downloader.