Unzip files (7-zip) via cmd command

I try to unzip a file via CMD.

So I install winzip (and its plugin to cmd), winrar and 7-zip.

But when I try to execute a command via the CMD:

7z e myzip.zip

It gives the next error:

7z is not recognized as an internal or external command

In addition, I added the folder of 7-z to the environment variables (Properties--> advanced --> Environment Variables --> user variable --> choose path, and add C:\Program Files\7-Zip

What can be the reason?

Doing the following in a command prompt works for me, also adding to my User environment variables worked fine as well:

set PATH=%PATH%;C:\Program Files\7-Zip\
echo %PATH%
7z

You should see as output (or something similar - as this is on my laptop running Windows 7):

C:\Users\Phillip>set PATH=%PATH%;C:\Program Files\7-Zip\

C:\Users\Phillip>echo %PATH%
C:\Program Files\Common Files\Microsoft Shared\Windows Live;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Wi
ndows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\
WirelessCommon\;C:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\;C:\Program Files\Microsoft SQL Server\100\To
ols\Binn\;C:\Program Files\Microsoft SQL Server\100\DTS\Binn\;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Program Fil
es (x86)\QuickTime\QTSystem\;C:\Program Files\Common Files\Microsoft Shared\Windows Live;C:\Program Files (x86)\Notepad+
+;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;C:\Program Files\7-Zip\

C:\Users\Phillip>7z

7-Zip [64] 9.20  Copyright (c) 1999-2010 Igor Pavlov  2010-11-18

Usage: 7z <command> [<switches>...] <archive_name> [<file_names>...]
       [<@listfiles...>]

<Commands>
  a: Add files to archive
  b: Benchmark
  d: Delete files from archive
  e: Extract files from archive (without using directory names)
  l: List contents of archive
  t: Test integrity of archive
  u: Update files to archive
  x: eXtract files with full paths
<Switches>
  -ai[r[-|0]]{@listfile|!wildcard}: Include archives
  -ax[r[-|0]]{@listfile|!wildcard}: eXclude archives
  -bd: Disable percentage indicator
  -i[r[-|0]]{@listfile|!wildcard}: Include filenames
  -m{Parameters}: set compression Method
  -o{Directory}: set Output directory
  -p{Password}: set Password
  -r[-|0]: Recurse subdirectories
  -scs{UTF-8 | WIN | DOS}: set charset for list files
  -sfx[{name}]: Create SFX archive
  -si[{name}]: read data from stdin
  -slt: show technical information for l (List) command
  -so: write data to stdout
  -ssc[-]: set sensitive case mode
  -ssw: compress shared files
  -t{Type}: Set type of archive
  -u[-][p#][q#][r#][x#][y#][z#][!newArchiveName]: Update options
  -v{Size}[b|k|m|g]: Create volumes
  -w[{path}]: assign Work directory. Empty path means a temporary directory
  -x[r[-|0]]]{@listfile|!wildcard}: eXclude filenames
  -y: assume Yes on all queries