Hi Bernie
You don’t need to install WinZip as it is built in to the Windows XP OS, however as its loaded, double click the Zip file you downloaded and WinZip should open, you can then choose where you want to store the uncompressed files, (I suggest a new folder in My Documents) click Unzip and the uncompressed files will be transferred to the new folder, close WinZip and open the new folder, then look for the Icon called Setup.exe, double click the icon and follow the instructions to install OMB.
Hope this helps

Bill