I need to update Windows Installer to 4.5 on Windows XP (Hotfix KB942288) but it has to be done without a reboot. Some software we're trying to install requires WI 4.5 but it's on a computer that cannot be restarted. It runs on a multi-site HA VMWare ESX cluster and we need to keep it as close to 100% uptime as possible (Our SLA is 6 nines), the services it's running don't support Windows Server or their own HA/clustering so we must keep a single instance up all the time. We can't even run security updates.
Is there any way to get the WI 4.5 update fully installed without a full reboot?
I know nothing that needs 6 nines uptime should be run on a single instance, but the software doesn't support any form of clustering, failover, replication, HA etc. I've never had anything to do with this server before (I'm actually a UNIX sysadmin but I've been pulled onto this for some reason unknown to me).