If You have a trouble with upper download, You can try mirror:
Update from versions 1.00 - 1.05 to final 2.0 version: quadrax_iv_2.0_update.exe
Versions 1.00 to 1.03 include broken level 41, if you have ver 1 - 1.03, please update game with this update to ver. 2.0!
Versions 1.04 include level 85 with optical bug in upper right corner. The level is solvable if You know this bug...
Update can be used to any game version!
If You playing any modification, after update You must again install the same modification. (Updrade to upper version game don't affect.) (Update file size is 1 590 662 B.)
Now, You can download game from free game servers:
Attention! In this servers is probably version 1.03! Check You game version (left upper corner on the main game screen) and if version number is 1.03 or lower, do update to version 2.0!
INFO - NEWS! Portable version of Quadrax IV game You can download from Modifications section.