From NSIS Wiki
|Author: SpiderVenom (talk, contrib)|
A small (3KB) plugin that generates a standard ZIP CRC32 for any file you pass it:
CRCCheck::GenCRC "$SYSDIR\explorer.exe" Pop $R1 MessageBox MB_OK $R1This gives you a CRC for the windows explorer executable. If a CRC can not be generated, you get "0" in $R1. Specific error reporting will come soon.
Written in VC++ 7, it reuses the CRC code from VPatch, with a few tweaks.
Just extract CRCCheck.zip to your NSIS dir (with folder names), and everything will go in the right place. Check \Contrib\CRCCheck\Readme.txt for more info.