Cant open tar.md5 files to view the .img files 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 Odin for Samsung Devices. 

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. 

For example:


Lets say I download a new Modem called MODEM_S6102DXLC2_REV01.tar.md5
Open ODIN
Place MODEM_S6102DXLC2_REV01.tar.md5 in the 'Phone' or 'CP' section (Depending on Odin Version)
Flash Modem. 




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.