Nice non-install program to check file integrity

When working with computers every now and then I need to check the integrity of downloaded files. This is to make sure that the downloaded file has not been changed or modified, contains no viruses or spyware. Every reliable and self respecting software developer should publish a checksum together with the downloadable file on their websites. A typically checksum might look like something this: L9ThxnotKPzthJ7hu3bnORuT6xI.

Do check the file integrity there is a simple program made by Microsoft, called "Microsoft File Checksum Integrity Verifier". It is a no-install program which runs in command prompt. So, download it, extract to a convenient location (I just use disk D:) and put the file which intergrity you wann check at the same location. Then run the command from cmd:

fciv.exe -sha1 WhateverIsYourFilename.exe.

In this example SHA1 checksum algorithm is used,but there are many other hash functions such as MD5 etc.