|Do you have the user manual?|
If not, it's available here:
Whether you have it and have examined it or not, it has troubleshooting info in it.
"This problem has occured with each computer I have owned,..."
Huh? How is that even possible? Have they all been Acers?
Take a look at your Event Viewer entries (e.g. Control Panel - Administrative Tools). There may be an error entry there for every time Windows has booted that's related to this.
You could try disabling Startup Programs.
Start - Run - type: msconfig (click on OK or press Enter)
Startup tab - disable everything there from loading. If not everything was enabled, note which are enabled, or which are disabled, whichever yeilds you a shorter list, BEFORE you disable everything. (NOTE that many people have too many things that load there that DO NOT need to be loaded.) If the white windowdoes not appear thenext time you boot, one of the things you disabled from loading is what's causing the white window to appear.
When you make any change with msconfig, the next time you boot, you will get a pop up window for System Configuration, then a second one when you close that one - close both by clicking on the X in the top right corner if you don't want to make any more changes at that time. The first pop up window has a small box on the left you can click on to insert a checkmark if you don't want that box to pop up next boot - if you click on that to insert the checkmark, the second window will not pop up, and neither window will pop up after booting after that. If you don't click on that small box to insert a checkmark, both of those windows will appear each time you boot, unless you enable everything that was disabled, or only enable what was enabled previously.
When you have finished fiddling with msconfig, enable the things that you want to load, insert the checkmark in the first window the next time you boot if it appears.
Windows XP (and 2000) has an annoying glitch in displaying MSConfig - Startup listings. Before you disable entries there, the enabled entries are at the top of the list. If you then have disabled some entries, when you later go to re-enable them, they will probably not be in the same place in the list as they were before. Because of this annoyance, if you disable more than a few entries, it is a good idea to write down which entries you disabled when you disable them so that you can more easily figure out which ones to enable later.
You could try disabling running programs.
Start up Task Manager (e.g. press the Alt-Ctrl-Del keys at the same time).
Click on the Processes tab if that list is not already being displayed.
End the process for anything you think it might be - if the white window vanishes, that's the one.
If you're not sure what something is for, copy down the name of it and look that up on the web.
svchost.exe is a "slave" program that is used by one or several other programs that are not listed. You probably have several instances of it. If Ending one of those makes the white window vanish, go to the Microsoft web site and search for: "Process Explorer" - download it, install it, and run it - with that you can find the names of the programs that are using that instance of svchost.exe and disable individual programs from running.