cannot install avast4

when I try to install the program (setupeng, 3.999 kb)
I get the message " error 20000000B, invalid file signature, stup wille terminate. Details given are:

Cannot open reg. key:Software\Alwil Software\Avast\4.0
ERROR:Invalid file signature. Setup will terminate.

How come and What now?

Regards, oudeman

It is incorrectly downloaded file. The correct size is 6.5 MB. Try to use some download manager for getting files from the Internet.

thank you very much, kocour. everything is o.k. now.
it appears there is something wrong with the downloading facilities in opera (7.2).

regard, oudeman