Support for Windows Embedded 8.1 Industry on the HP t520, HP t620, and HP t620 PLUS Thin Clients

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The following items are stored on the Z: drive during the operation of the thin client:
• Browser web page cache
• Browser history
• Browser cookies
• Browser cache
• Temporary Internet files
• Print spooling
• User/system temporary files
The HP Unified Write Filter Configuration utility is a customized graphical user interface (GUI) enabling the management and
monitoring of the Unified Write Filter (UWF) included with Windows Embedded 8.1 Industry.
Flash storage and memory
Windows Embedded 8.1 Industry requires a minimum flash memory capacity of 32 GB and a minimum of 4 GB SDRAM
memory. HP recommends a 64 GB capacity flash memory module for optimal performance. If upgrading an existing system
configured with a 16 GB or smaller flash memory device, contact your HP representative regarding available HP options.
Note
If the flash or SDRAM memory are not genuine HP parts, HP will not support or warranty issues with the third-party parts.
Operating system support
After a customer enters a Volume Licensing agreement with Microsoft and creates a custom image, the support for that
image changes hands. Traditionally, support for Windows Embedded operating systems has only been available through the
OEM. The creation and support of Windows images handled through a Volume License Agreement are the responsibility of
the customer, the third-party ISVs, and Microsoft.
Before creating and deploying a custom Windows Embedded 8.1 Industry image, the customer should complete a thorough
review of the Windows services, user setup, and applications to understand what might be writing to the flash drive (by
default, drive C:). While UWF is enabled, writes that would normally be made to the flash drive are redirected to the write
filter cache, which is set to a maximum size of 2048 MB by default. This space can be filled up quickly if any services or
applications are attempting to regularly write data (such as log files) to the flash drive.
Once the review is completed, an action plan should be developed to deal with these items, if found. Possible actions
include:
• Disabling unneeded services
• Redirecting temp files and logs to the RAM drive (Z:) instead
Following these guidelines will help ensure that your HP thin client remains stable and in working condition. See
Unified
Write Filter for more information.
Service
In the event that a thin client system comes to HP for service, all aftermarket options (flash and memory) should be
removed from the thin client, because these aftermarket options might not be returned with the system. When the system
is returned, it ships as initially configured in the factory, including the original operating system. You can reinstall the
aftermarket options and your custom image after the thin client is returned.