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

HP software support

HP offers several software programs designed to enhance the thin client experience. The software supported for thin clients

based on Windows Embedded 8.1 Industry includes the following:

• HP Device Manager

• HP Velocity

• HP Easy Shell

• HP Hotkey Filter

This software is supported as long as the HP driver pack is installed first on the thin client. The driver pack can be

downloaded from the appropriate product support page (t520, t620, or t620 PLUS) at http://www.hp.com/support

. In the

case of HP Device Manager, the HPDM Agent installation files can be found on the HPDM Repository server in the HPDM >

Repository > Agents folder.

Unified Write Filter

One of the most important features of a Windows Embedded operating system is its ability to restrict write activities and the

storage of data to the local client. Unified Write Filter (UWF) is a critical security and function feature designed to prevent

data from being written to the thin client flash memory module. Because nothing is written directly to the non-volatile

memory, restarting the thin client returns the system to its original state. UWF helps to preserve the flash memory module

from excessive write/erase activity and to protect the system from damaging viruses and malware.

For information about UWF on HP thin clients, see the Administrator Guide for Windows Embedded 8.1 Industry Pro on HP

Thin Clients.

For general information about the architecture of UWF, go to

https://msdn.microsoft.com/en-

us/library/dn449332(v=winembedded.82).aspx.

Caution

HP recommends and encourages proper write filter usage for all thin client operations. Proper usage includes making sure

that the write filter is enabled during standard user (non-administrator) operation for thin client systems configured with

relatively small flash memory devices. In these use cases, UWF should only be disabled temporarily by administrators to

make necessary changes and updates to the system, and should be re-enabled as soon as the updates are completed.

If an administrator determines that UWF must be disabled to properly support the thin client’s necessary operation and

tasks, care must be taken to ensure that the system’s flash memory module has sufficient capacity or technology to

support a large amount of write/erase operations. In most cases, 64 GB is the minimum capacity for operations with UWF

disabled; however, HP recommends at least 128 GB to ensure the performance and longevity of the system.

If your operation requires using thin clients with UWF disabled, contact your HP representative to ensure that your thin client

assets are properly configured to support your usage requirements.

HP further recommends that you never enable the Windows Page File feature due to the high volume of write/erase actions

this feature produces. This Windows feature is designed for PC operations involving computers configured with high-

capacity storage drives. The use of the Windows Page File feature on a thin client results in the premature wear on the

relatively small capacity of a thin client flash memory module and decreased system performance. If the flash memory

module is sufficiently worn, you must replace it to continue operating the system.