how do i tell if the downloads md5 hash matches?

Hello, this is probuly an easy question for some, but here it is..

I have seen websites where the download from the site has a md5 or sha1 hash posted to make sure you are downloading the real file from the site and not a fake one..

How do i tell after i download the file if the hash matches? I went to file properties on the download and did not see any hash or anything, is there a text file included in the zip or where do i find the hash once downloaded to match it to the websites download so i know im getting the real file and not a virus or something? thanks!

 

For Windows this should be safe enough. When burning with some applications (k3b) it checks it automatically at the start.
http://portableapps.com/apps/utilities/winmd5sum_portable

 

thanks!

How does the program go about getting the md5 hash from a zip or program? do they use winrar or 7-zip to add the md5 hash into the .zip or .rar? or is it some kind of assembly code or something added into the .exe file somewhere? just curious as to how it works, thanks

 

MD5 Check Sum should come with the download or be listed separately as a test file on the same page.

 

http://en.wikipedia.org/wiki/MD5
http://www.pc-tools.net/win32/md5sums/
Never gave it that much thought until now, but here are a few reads Google suggested.