Error 53 - cannot create application desktop

If you encounter this error please modify SessionViewSize and SharedSection setting like described below. After each change the server machine reboot is required.

Every GUI session (one Winflector user) creates one desktop object in the system memory allocated for desktops. If the system is out of desktop memory you will get an error:
"Cannot create application desktop"

On Vista, Windows 2008 and Windows 7 systems desktop memory is allocated dynamically and does not
require adjustments. On Windows XP and Windows 2003 systems you may need to adjust the desktop memory settings.

The amount of memory accessible for all desktops created by GUI applications and console desktop can be set in MB (Megabytes) by editing the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\
CurrentControlSet\Control\Session Manager\Memory Management\SessionViewSize

The amount of memory allocated for each created desktop object (every GUI session) and for console desktop can be set in KB (kilobytes) by editing the following registry entry:

HKEY_LOCAL_MACHINE\SYSTEM\
CurrentControlSet\Control\Session Manager\SubSystems\Windows
You need to modify the second value after text SharedSection=
This value should not be set below 1024 (1MB) or your main Windows console may not start properly. Decreasing this value can be considered on Vista and Windows 2008 as well because it allows for decreasing memory usage.

The default values for global desktop memory pool (SessionViewSize) and for a single desktops are as follows:

WindowsXP (32-bit)
48 MB = SessionViewSize (registry default value) - increase
3073 KB = single desktop, SharedSection second parameter - decrease

Windows Server 2003 (32-bit)
48 MB = SessionViewSize (registry default value) - increase
3073 KB = single desktop, SharedSection second parameter - decrease

Windows Server 2003 started with 3GB option (32-bit)
20 MB = SessionViewSize (registry value is ignored)
3073 KB = single desktop, SharedSection second parameter - decrease

Windows Server 2003 (64-bit)
104 MB = SessionViewSize (if we don't change the register value) - increase
20 MB = single desktop, SharedSection second parameter - decrease

Windows Vista (32-bit)
SessionViewSize dynamically adjusted
3072 KB = single desktop, SharedSection second parameter - decrease

Windows Vista (64-bit) and Windows Server 2008 (64 bit)
SessionViewSize dynamically adjusted
20 MB = single desktop, SharedSection second parameter - decrease

Windows Vista SP1 (32-bit) and Windows Server 2008 (32 bit)
SessionViewSize dynamically adjusted
12288 KB = single desktop, SharedSection second parameter - decrease

Windows 7 (32-bit)
SessionViewSize dynamically adjusted
12 MB = single desktop, SharedSection second parameter - decrease

Windows 7 (64-bit)
SessionViewSize dynamically adjusted
20 MB = single desktop, SharedSection second parameter - decrease