Im trying to open my stock rom file that i downloaded from sam firmware and when I try open it with winrar it says: The archive is either in unknown format or damaged. so i tried taking the .md5 extension away and still no luck? Other people have managed to do this besides me?
Generic Samsung Firmware MD5 Information:
You can flash an MD5 file via
An MD5 file is just a .tar file with a checksum included. Odin can recognise both, and you an even just remove the .MD5 and have .tar on the end, rather than the usual .tar.md5 extension Samsung software has. A tar file is just a *NIX archive file to all intents and purposes.
Note: MD5 cannot be flashed by CWM or TWRP or any other custom recovery.
Opening Tar Files:
To open a .tar file you can use 7-Zip in Windows.
Link to 7 Zip Page note it mentions Tar explicitely on the page.
Here is a list of free archive software for windows many of which can open tar files.
Source: MD5 file extension
In other words, you may have downloaded the checksum file for the application/file/etc that you are attempting to download. The reason WinRar can't open it, is because WinRar is searching for compressed archives, not a checksum file.