QUAKE DEMO
1. Have
XAD installed.
2. Download
quake106.zip3.
xadunfile quake106.zip t:4.
xadunfile t:resource.1 t: id1/pak0.pak5. copy t:id1/pak0.pak to your quake game directory, for example:
copy t:id1#? work:games/quake/ allQUAKE FULL
This depends on the version of the game, but the simplest solution is to install the game and then copy the .pak files from the game ID1 directory.
To be honest this isn't exactly rocket science.