If you're running into stability problems with Apache on Windows and can't switch to Linux, doing the following seems to help quite a bit.
First, find these lines in your httpd.conf file and uncomment them:
Then right below those lines, add this line:
Particularly if you're seeing errors along the lines of "The specified network name is no longer available. : winnt_accept: Asynchronous AcceptEx failed" or "The semaphore timeout period has expired. : winnt_accept: Asynchronous AcceptEx failed" that last line should eliminate those errors.
If you're interested in learning more about what's behind these errors, there's a nice post about it on the "My Digital Life" blog.