WAS 640 preview - fail to unzip the installation file

I have downloaded the WAS 640 preview and try to install it. However, when I try to unzip the file "SAPinst_SP_WAS640.exe", I got an error message on the file "sapjeecor04_0.sca" which said that "bad CRC ce9d00e6 (should be 7202a334)". It seems that there is some problem in the zip file. How can I fix this?