There are several little tricks in this one.

The Pulse client changes it's product code depending on the region it detects the device is located in. Keep an eye on the Pulse release notes for each version. Though they have not yet been officially released. Contact the Pulse Support for the codes if you plan on installing outside your nation. There are different product codes for the US, France, Germany, Japan, China, Poland, Korea, Italy, Taiwan, and Spain. It's a lot of noise so I'll post them if someone asks...and I see the request. They 'morph' from the original product code through a custom action, I have been unable to extract the codes. The process is detailed in a verbose log.

If you plan on placing pulse into an image, utilize the property and value 'SHAREDINSTALL=1' to avoid a unique key being set on every devices imaged with pulse. This is also something that will help if you have any errors with their jamcommand launching during install.

If you have issues importing a config file at the time of installation it can be imported with this command:
"[root]\Common files\Juniper Networks\JamUI\Jamcommand.exe -importfile YOURCONFIG.jnprpreconfig"

With no special considerations your install cmd line should look like this:

Msiexec /i JunosPulse5-1-7.x64.msi /qn CONFIGFILE=YOURCONFIG.jnprpreconfig REBOOT=ReallySuppress /l*v C:\temp\Pulse517.log

The configuration file is optional and it should come from the person or team administering the VPN appliance. If imported you need to use the full path to the file, no matter the method.