NSIS installer errors

I get a repeat error message:NSIS isnstaller is corrupt and will not install w/o changing some command function or another . I have tried everything I can think of and cant seem to solve the problem, including redownloading numerous times, can someone help please?

Where does this error appear?

You should contact the author of that installer. The file on the server is probably corrupted. Another possibility is that your computer is infected with a virus that modifies your downloads.

it comes upo on the windows system error and it wont allow it to load,(the Winamp program)