Problem with Ruby 1.9 64 bit Gem and Zlib dll

I found a solution to run gem command in a windows 7 64 bit environment

I know that ruby 1.9 64 bit have a lake on zlib.so so download the last version of the dll at this address :

http://www.winimage.com/zLibDll/zlib125dll.zip

copy the zlib125dll.zip\dllx64\zlibwapi.dll into your ruby\bin folder
rename the dll into zlib.api

done !