This web page has an explanation of "System Resources" in Windows.

http://www.apptools.com/rants/resources.php

The following was written by Ron Martell, a Microsoft MVP:

Here is my standard explanation regarding System Resources, which may
be of some assistance.

System Resources refers to two 64K blocks of memory that Windows
allocates to programs for tracking purposes. These blocks are called
User Resources and GDI Resources respectively and Windows reports
whichever has the least available free space as the value for "Free
System Resources".

The value of Free System Resources should not be a concern unless and
until you start getting "System Resources are getting low" type
warning messages, which generally happens at about the 10% level. In
test circumstances it has been shown possible for a computer to
operate at full performance with System Resources showing zero percent
free.

System Resources are totally unrelated to the amount of RAM installed
in your computer and adding more RAM will not affect the System
Resources (unless you start running more applications because you have
more RAM).

System Resource usage is determined by the number and type of
applications that you have running on the computer. Certain types of
applications have been shown to be especially demanding in terms of
System Resource usage:
- "Eye and Ear Candy" such as Active Desktop View As Web Page,
sound effect schemes, animated mouse cursors and desktop icons, and
fancy screen savers.
- Web browsers, as each open browser window requires additional
resources.
- Multimedia applications of all types
- System monitoring utilities such as Norton SystemWorks.

If you are using any applications that have the ability to "preview
fonts in fonts list" such as Office 2000 then all of the installed
fonts will be loaded into GDI resources when the application is
launched. This will result in the usage of approximately 1% of GDI
resources for each 64 fonts that are installed. If no such
applications are in use, or if the "preview fonts in fonts list" is
turned off then resources will only be consumed by those fonts that
have actually been used by windows or by an application.

If you are running any 16 bit applications (Windows 3.x) then Windows
95/98/Me will treat the System Resources allocated to all of these
applications as one block and will not release any of them for reuse
unless and until all of the open 16 bit applications have been closed.

Also, when an application is loaded it is quite common that it will
also require some additional Windows components to be loaded as well.
However, when that application is closed Windows will, by design,
retain the Windows components because they are likely to be needed
again. Therefore the resources initially allocated when an
application is opened will not all be released when that application
is closed. Most, but not all.

Footnote:
To be absolutely technically correct, there are 5 System Resource
heaps not just 2, the two 16 bit 64K ones plus three 32 bit ones. The
32 bit ones are big enough so that there has never been a documented
instance of resource usage problems caused by them, so it is simpler
to pretend they do not exist and just focus on the two 64K resource
heaps when troubleshooting system resource related problems.


Bill Starbuck (MVP)