Hi,
Video and audio are very bad running video Intro , I've tried setting all graphics mode but don't solve....
Can You help me please ?
Thanks!

I also have a lot of stuttering in the videos and a bit in the game. I contacted gog but their tips didn't help not one bit.

Not so sure about the video issue, but the GOG Wiki does have something about skipping and popping audio.
[url=http://www.gogwiki.com/wiki/Crusader:_No_Regret]http://www.gogwiki.com/wiki/Crusader:_No_Regret[/url]

Skipping/popping audio

Since GOG tends to utilize years-old DOSBox settings standards, several issues permeate through their DOS releases. Skipping audio is among them. Though there is no universal solution for this issue, adjusting several settings in the [mixer] section of a DOSBox configuration file helps alleviate most problems.

Open "dosboxREGRET.CONF" with a text editor and edit the values under [mixer] to the following:
[mixer]
nosound=false
rate=44100
blocksize=1024
prebuffer=50