cannot open downloads

If I try to download a program from the internet (example) adobe reader
from tucows. after the file is downloaded and I click to open it I get the following message

this file does not have a program associated with it for performing
this action. create an association in the folder options control panel

error 1155 unable to lunch aom file. create process return code 10348100

this has just started. wonder whats happend??

 

What is the extension of the files example : .exe .zip .rar