Under Windows, using security software and certain operating system features to prevent the computer from various attacks and security hazards is a common and highly recommended practice. However, any misconfigured security feature can cause cause problems using DC++ ranging from partial feature blocking to a complety blocked network access. If you experience connection problems (can't connect to any hub or download any hublist, file transfers aren't possible in any direction, neither downloads nor uploads) while your other installed programs are able to access the Internet without problems then it's possible that something blocks DC++.
Whether it is the operating system's built-in firewall or any installed 3rd party security software that keeps DC++ from work, you must find out why's the blocking and how to unblock DC++.
You might suspect that DC++ is blocked if you experience any combination of the following:
Another way to check if DC++ is blocked is to go the Help/About menu in DC++ and check if it can download the Latest Version number (bottom box of the window). A version number should appear in the box soon. If you get error message instead it means something is preventing DC++ from accessing the Internet.
Important: If you have problems with searches and/or file downloads only, while uploads and other functions are working properly then most likely the problem is with the connectivity settings instead. While it does not hurt to go on with this FAQ and check if DC++ is properly allowed in various places, if the case above applies to you, you may solve the problem sooner if you follow the Connection setup guide instead.
The firewall component included in recent Windows operating systems is enabled by default. While it does not offer a plethora of options, its suitable to use by itself for protection. If it's enabled and you have problems accessing the Internet with DC++ the best practice is to check for and delete existing exception(s) for DC++ then let the operating system properly readd it at next start of the DC++ application. To do this, close DC++ and
If the above doesn't help its wise to enable logging of packets that the firewall drops for troubleshooting DC++ (or any other applications') access. To do this,
The method for unblocking programs in 3rd party security software varies from product to product. Check the program's help or manual for proper instructions. The best general practice is to exit DC++ and remove ALL the rules for DC++ in the appropriate configuration place of your security software. If you run a complete security suite you may have to unblock DC++ in more parts of the application (eg. in the firewall part and the application control part).
After deleting the rules restart DC++. In most cases you'll be shown a popup window or a taskbar alert from the security software where you can properly enable (make an exception rule for) DC++.
Some additional tips: