After downloading the file and extracting the archive, run unecm.bat to extract the image into useable form. After that either burn the image to disk or mount the .cue file into virtual CD drive program (eg. Daemon tools or Alcohol 120%)

To make the game run in DosBox, you have to change the DOS4GW.exe, either copy it from any other DOS4GW game or alternatively download dos32a and copy the dos32a.exe into Absolute Zero install directory and rename it into dos4gw.exe

To install the patch, just extract the archive Patch.rar and copy the contents into the game directory, overwriting all files.