This entry is a user-made guide and not verified by any eMule developer, but is still a helpfull addition for most users. You you can find questions and comments on this topic in a dedicated thread on our forum.
I suggest moderator to post some sticky here with known programs, causing (sometimes) problems with eMule. (Not for hardware driver problems!)
From my personal experience, other users support and reading forums I start with next:
1. PopUp Stopper freeware edition (crash while selecting downloads screen) - fixed by disabling it
2. Norton Anitivirus (reported various crashes during completion) - fixed by disabling virus scanning of eMule temp and income folders; or by using McAffee AV instead
3. ZoneAlarm freeware edition (server disconnects while searching) - fixed by changing protection mode from high to medium
4. Pasakche Proxy Software causes Windows crashes when using with eMule.
5. Norman Virus Control makes eMule crash at start.
6. NOD32 - antivirus software, can cause freezes or crashes. Help: Disable IMON during installation!
Of course, these problems may occur only on some systems, not on all.
Post here only confirmed cases - when removing/disabling, or reconfiguring reported software solved eMule problems!