Thanks, John, for all the information and answers.!!! I do appreciate your time, and I think I am learning some things. :-)
I believe the best answer for the thought behind this, is in using the USB "as Ready Boost" (on the XP system). [This is what I am being told is possible to do]. ~now I am learning this is not so. There are many youtube videos and articles online showing "how to add RAM to XP with a USB flash drive." However, most that I have seen, are adding 2GB to a system which probably had only 1GB of RAM installed. (The publish dates of many of these are 2009-2011. Whether they even work, or not, I can't say.)
As far as increasing the page file size in C, on the XP machines, I was following the instructions of the Microsoft article (also linked above): ""How To Set Performance Options in Windows XP"
http://support.microsoft.com/kb/308417/en-us
" The recommended minimum size is the same as 1.5 times the RAM on your computer, and 3 times that figure for the maximum size."
You can see that they mention to set the initial and the max at 1.5 and 3x the installed RAM values, (which exceeds the 4096M limit I am encountering).
This IS a rebuilt machine, and I do not know if the 4096MB value is a default Windows XP value, or if it is based on the 2GB RAM which I believe the machine was originally installed with. (The rebuild included a new 1T hard drive, motherboard, and 4GB RAM).
If you are accusing me of doing this: 'home machines that are yanked about and "experimented" with in Jekyll Hyde kind of fashion that some home users give to their computers! Well, sir, I am doing research, and asking questions before proceeding. I appreciate the wisdom of others, and those willing to share it. Knowledge is wisdom, and questions are the beginning of wisdom. I am trying to increase the performance of my machine, responsibly, not ruin it. I am a technician/electrician; not a "button-pusher"; "Let's see what happens if I press this button!" Please don't judge me like that.
Q: why do you think that you need all that much paging space? A: M*a*f*i*a*Wars is a Zynga game on facebook, which seems to consume a lot of RAM. There are not a lot of flashy action graphics, necessarily, but a lot of actions being performed; clicks being sent over the internet. Many, MANY clicks per second, per minute. I notice (on the XP machine's Task Mgr), in the Page File graph, the numbers will creep up to 2.88G. This is with one browser open, and 4 tabs (or 'users' within the browser; Chrome-based browser, open). As the PF graph rises, the computer seems to slow. (CPU usage typically 25-50%) dual-core 3.0GHz processor, seems OK, but sometimes at 60-80%.
Question: Does this indicate that the RAM is full, and this data is being 'cached' in the hard disk's page file (virtual RAM)? In comparison, I have a laptop notebook pc with Windows 7 Home Premium, and the Task Mgr shows RAM, as you know. A similar thing occurs. As more game tabs are opened, the RAM 'usage' rises, and computer response slows (CPU % rises). The idea, apparently, is that by adding more RAM, we can keep the cpu running at a lower % (faster). So, to summarize, I still am not sure that the settings for C drive Initial size, and Maximum Size, in Virtual Memory are set correctly, based on the current installed RAM. I will search for the information that you mentioned, on how to make the appropriate changes. I recall seeing on the Microsoft site that no discussion about performance would be complete without discussing adding more RAM. Thanks, again!
Also, in Performance Settings, on the XP machine, I have selected "System Cache" as opposed to "Programs". This was also mentioned in the article, as a possible solution. As I do not have many programs running while I am 'playing' M*a*f*i*a*Wars game.
edit to add:
Interesting reading on the Gavotte Ramdisk. ...Unsure about installing it. Seems to be a lot of conflicting comments about it.
But, can I simply add the /PAE switch to the boot.ini file, and have the OS use more of the hard disk for paging file, if needed, by increasing the PF sizes of C in virtual memory?
Will I gain anything? (drop in cpu % / less lag /faster response)
Is it true that the Windows XP OS only uses or 'sees' 3GB of the 4GB installed RAM?