I've used GetDown from the getdown-maven-plugin from joxley with the GetDown-Version 1.2.
In case the enduser has a company laptop withou admin rights and the userdir is on a share.
When the update is executed i will get the follwing exception in the launcher.log and the update is not happend.
2014/07/01 17:35:55:699 INFO e.a: ------------------ VM Info ------------------
2014/07/01 17:35:55:715 INFO e.a: -- OS Name: Windows 7
2014/07/01 17:35:55:715 INFO e.a: -- OS Arch: x86
2014/07/01 17:35:55:715 INFO e.a: -- OS Vers: 6.1
2014/07/01 17:35:55:715 INFO e.a: -- Java Vers: 1.7.0_25
2014/07/01 17:35:55:715 INFO e.a: -- Java Home: C:\Users\TMC27161\Documents\ALR\eAlarmScope\eAP Project V 0.9_NEW\jar Version\jre7
2014/07/01 17:35:55:715 INFO e.a: -- User Name: TMC27161
2014/07/01 17:35:55:715 INFO e.a: -- User Home: \\sg1005p-v1\TMC27161$
2014/07/01 17:35:55:715 INFO e.a: -- Cur dir: C:\Users\TMC27161\Documents\ALR\eAlarmScope\eAP Project V 0.9_NEW\jar Version
2014/07/01 17:35:55:715 INFO e.a: ---------------------------------------------
2014/07/01 17:35:55:731 INFO e.a: Failed to find proxy settings in Windows registry [error=java.lang.UnsatisfiedLinkError: no jRegistryKey in java.library.path]
2014/07/01 17:35:55:731 INFO e.a: Checking whether we need to use a proxy...
2014/07/01 17:35:55:731 INFO e.a: Dropping status 'm.detecting_proxy'.
2014/07/01 17:35:55:731 WARNING e.a: run() failed.
java.lang.RuntimeException: Invalid appbase 'null'.
at com.threerings.getdown.data.Application.getConfigResource(Unknown Source)
at com.threerings.getdown.launcher.Getdown.detectProxy(Unknown Source)
at com.threerings.getdown.launcher.Getdown.run(Unknown Source)
2014/07/01 17:35:55:731 INFO e.a: Dropping status 'm.init_error|~Invalid appbase 'null'.|'.