In Control Panel on USERS I get a blank window and thus cannot set users and passwords. The way MS controls everything relating to their system and locksusers out (to "protect" them? ) now has me stumped. At the time this started I also can no longer access the FIND and HELP function.
I wanted to refresh the XP system with my legit XP CD I am informed that I cannot do that because the XP system on my computer is a newer version. Does MS mean I have to buy a brand new XP Professional?
Stumped and hoping a resident guru might have a suggestion. BTW: when contacting MS support(?) system, I am told they will gladly let me email as long as I shell out $49.00 WITH NO PROMISE  of any solution being offered.

At the command prompt (Start/Run) Type the following line
  regsvr32 C:\WINDOWS\system32\shgina.dll

Thanks for the suggested cure. I did run it and was told the function was successfully installed. However, all of the three problem areas still exist: Search Window is blank, So is the user setup panel . The System restore after entering user name and pass word now comes up with a blank window and some disk activity but now entry fields

Try this -- longshot but worth a try.
Right click on the computer icon and choose manage.
In the window that opens up expand "Local Users and Groups" and click on Users.
In the right-hand panel right-click on an open space and highlight "New User".
Create a new user.
Best of Luck