I should find cis- regulatory elements in promoter region of some genes. I used PlantCARE date base but its results are in "tar.gz" files. How can I extract "tar.gz" files in windows ?
Use something like 7zip to unpack the .tar.gz file. Upon installation, 7zip adds context menu options to windows explorer that allows you to unpack files with a right click.
Also note that you'll have to unpack .tar.gz files twice. Once to turn the file into a .tar, and once more to get to your desired files.
You can follow the tutorial section on this wiki: https://wiki.haskell.org/How_to_unpack_a_tar_file_in_Windows#7-Zip
All the command line options described are the same as right clicking on the file and selecting 7zip from the context menu.