Unable to allocate more than 1000 window handles

  • Thread starter Thread starter Charles Calvert
  • Start date Start date
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Charles Calvert

I've run into a problem recently on XP (SP1) that seems to prevent the
system from allocating more than 1000 window handles. This is a very
small number of handles and is preventing me from running more than a
few programs at once. I suspect that a registry entry was changed by
a recent windows patch or by a third party program meddling where it
shouldn't. Has anyone seen this problem before? Any ideas? I spent
several hours googling the usenet archives, but was unable to find
anything that seemed relevant.

Important note: every button, menu, list box, combo box, text box or
other control is a window or combination of several windows (like a
combo box). Each window is managed by the program via a window
handle. When I say that my installation of XP won't allocate more
than 1000 handles, that counts each and every control. For example,
I'm running Outlook 2K and it has 60 window handles allocated, even
though only the main window is open. (If you want to see what is
allocated on your system, check out Task Info:
<http://www.iarsn.com/>).
 
Handle Management
http://www.codeproject.com/threads/handlemanager.asp

--
Carey Frisch
Microsoft MVP
Windows XP - Shell/User

Be Smart! Protect Your PC!
http://www.microsoft.com/athome/security/protect/default.aspx

:

| I've run into a problem recently on XP (SP1) that seems to prevent the
| system from allocating more than 1000 window handles. This is a very
| small number of handles and is preventing me from running more than a
| few programs at once. I suspect that a registry entry was changed by
| a recent windows patch or by a third party program meddling where it
| shouldn't. Has anyone seen this problem before? Any ideas? I spent
| several hours googling the usenet archives, but was unable to find
| anything that seemed relevant.
|
| Important note: every button, menu, list box, combo box, text box or
| other control is a window or combination of several windows (like a
| combo box). Each window is managed by the program via a window
| handle. When I say that my installation of XP won't allocate more
| than 1000 handles, that counts each and every control. For example,
| I'm running Outlook 2K and it has 60 window handles allocated, even
| though only the main window is open. (If you want to see what is
| allocated on your system, check out Task Info:
| <http://www.iarsn.com/>).
|
| --
| Charles Calvert | Software Design/Development
| Celtic Wolf, Inc. | Project Management
| http://www.celticwolf.com/ | Technical Writing
| (703) 580-0210 | Research
 
Handle Management
http://www.codeproject.com/threads/handlemanager.asp
Click to expand...

While that's an interesting piece of code, it doesn't address my
problem. I suspect that something in my explanation was confusing. I
apologize. The problem allocating handles is not restricted to my
code. No program can allocate another handle if there are 1000
handles already allocated by all programs combined.

I was talking to someone else about this after I posted my original
message and they wondered if it might be specific to my login. To
test this I logged in under another username and was unable to
replicate the problem. I opened programs until I got 1400+ handles
allocated and got no errors.

This leads me to believe that it is a registry setting specific to my
login that has been changed. The question is which one?
 
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