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Is it safe to remove duplicates from the Path Variable ? The Path Variable of my Windows 7 OS looks like this:

1  C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;
2  C:\Program Files\Common Files\Microsoft Shared\Windows Live;
3  C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live;
4  C:\windows\system32;
5  C:\windows;
6  C:\windows\System32\Wbem;
7  C:\windows\System32\WindowsPowerShell\v1.0\;
8  C:\Program Files (x86)\Common Files\Roxio Shared\DLLShared\;
9  C:\Program Files (x86)\Windows Live\Shared;
10 C:\Program Files\MiKTeX 2.9\miktex\bin\x64\;
11 C:\Program Files\Microsoft\Web Platform Installer\;
12 C:\Program Files (x86)\Microsoft ASP.NET\ASP.NET Web Pages\v1.0\;
13 C:\Program Files (x86)\Windows Kits\8.0\Windows Performance Toolkit\;
14 C:\Program Files\Microsoft SQL Server\110\Tools\Binn\;
15 C:\Program Files\Java\jdk1.7.0_07\bin;
16 %systemroot%\System32\WindowsPowerShell\v1.0\;
17 C:\MySQL\bin;
18 %systemroot%\System32\WindowsPowerShell\v1.0\

There are some duplicates but i am not sure if i can just remove them. The lines 7,16 and 18 look identical to me, so can i just delete two of them or does %systemroot% and C:\windows make a difference ? Also is it safe to remove line 2,3 and 9, because i do not use Windows Live ?

(Type sysdm.cpl in Win+R) or (Win+Break)

share|improve this question
I see only 1 dup. But you can always remove real dups. – ott-- Jun 20 '13 at 19:08
@ott-- so there is difference between %systemroot% and c:\windows ? That means i can only delete the last line ? – Devid Jun 20 '13 at 19:10
The %systemroot% is evaluated at runtime and can be different from c:\windows\ then. – ott-- Jun 20 '13 at 19:13
up vote 1 down vote accepted

Deleting duplicates in the Path environment variable will not change anything. However,

The %SystemRoot% variable is a special system-wide environment variable found on Microsoft Windows NT and its derivatives. Its value is the location of the system directory, including the drive and path. The drive is the same as %SystemDrive% and the default path on a clean installation depends upon the version of the operating system. By default, Windows NT 5.1 (Windows XP) and newer versions use \WINDOWS, Windows NT 5.0 (Windows 2000), Windows NT 4.0 and Windows NT 3.1 use \WINNT, Windows NT 3.5x uses \WINNT35, and Windows NT 4.0 Terminal Server uses \WTSRV

It should be safe to remove the [%systemroot%, C:\windows] duplicates if you are using windows XP or newer.

share|improve this answer
Thanks, so i can remove line 16 and 18, right? – Devid Jun 20 '13 at 19:20

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