[...] On the UBB side we have 25,000 members and 400 forums, which I believe makes us one of the largest Windows installs.
[...]
We have a gig of RAM and oodles of disk space. The server is usually only 20% busy so it's not maxing out the processor.
A single gig of RAM for such a huge site
. If you are sure the reason for crashing is not a hardware failure or such, the first thing I would do is to add more RAM. Configure MySQL to hold all indexes into RAM to relieve hd load.
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