From the 7-Zip Help file:
a (Add) command
Adds files to archive.
Examples
7z a archive1.zip subdir\\adds all files and subfolders from folder subdir to archive archive1.zip. The filenames in archive will contain subdir\\ prefix.
7z a archive2.zip .\\subdir\\*adds all files and subfolders from folder subdir to archive archive2.zip. The filenames in archive will not contain subdir\\ prefix.
cd /D c:\\dir1\\
7z a c:\\archive3.zip dir2\\dir3\\The filenames in archive c:\\archive3.zip will contain dir2\\dir3\\ prefix, but they will not contain c:\\dir1\\ prefix.
So the command you\'d want would be: 7za.exe a folder1.zip .\\folder1\\*
Also, pay attention to 7-Zip\'s handling of wildcards. It doesn\'t treat *.* as "all files" -- it means "all files with a period in the filename." Extension-less files will be missed. If you really want all files, just use * instead.
Finally, the -tzip parameter isn\'t needed if the archive filename ends in .zip. 7-Zip is smart enough to figure out which format you want in those cases. It\'s only required when you want a custom extension (e.g. 7za.exe a -tzip foo.xpi <files> for a Mozilla Add-on).