Keeping Your IIS Site Online

If you are hosting a site with Microsoft Internet Information
Services (IIS) 7.0, you should be aware of a potential bug that could take your
site offline.
IIS may not always get along with your antivirus updates.
DHIT recently encountered an issue in which a McAfee antivirus update causes a
key DLL to stop loading and IIS Application Pool to stop, which consequently disables
website hosting. When attempting to load an IIS-administered site, you will see
a  503 error (Service Unavailable):

Error caused by IIS issue

The particular issue may arise if a component of your antivirus
software is removed
or expired.
For example, your McAfee Host Intrusion Prevention client could
be inadvertently updated without all necessary components, uninstalled or
otherwise corrupted.
The fix for this issue is quick
(and relatively painless), involving a few
edits to the applicationHost configuration
There are other, related IIS issues detailed in Microsoft
support documentation here.
While the fix for this bug straightforward, catching these issues
in a timely manner may not be. DHIT uses Microsoft Internet Information
Services in a variety of implementations for our applications and has
experience ensuring hosting stability.
We recommend not only staying current on Windows and
antivirus software updates, but also maintaining a level of support to ensure
that potential issues are monitored and remedied quickly to minimize downtime
and vulnerability.

DHIT offers tiers of support to accommodate not only ongoing
software customization but server continuity. Please contact us with any
questions about this issue and keep your health data environment running