The auto-install of the jdk (7u7) hangs on my windows slaves. It seems that the command contains too many "\". The console output shows:

[JDK_7u7] $ C:\Jenkins\tools\JDK\JDK_7u7\jdk.exe /s /v /qn /L \"C:\Jenkins\tools\JDK\JDK_7u7\jdk.exe.install.log\" REBOOT=ReallySuppress INSTALLDIR=\"C:\Jenkins\tools\JDK\JDK_7u7\"

Running that command manually on the slave gives a popup(see attachment)

To make it work I had to remove 4 "\". Seems like there might be some escape character that actually is output as the command? This command runs successfully:

[JDK_7u7] $ C:\Jenkins\tools\JDK\JDK_7u7\jdk.exe /s /v /qn /L "C:\Jenkins\tools\JDK\JDK_7u7\jdk.exe.install.log" REBOOT=ReallySuppress INSTALLDIR="C:\Jenkins\tools\JDK\JDK_7u7"