Not terribly exciting... The server AN lives on has - for legacy support of some aged sites - been running IIS in 32 bit mode to continue support for some old school server components that won't work in 64 bit mode.
Bored yet?
I found I Had to switch to 64 bit, partly as part of scheduling a server transfer later this year to a newer and much more powerful box, and partly so I can use .NET 4 (which you can't if running 32 bit). It was planned, and all going to plan, until something called ISAPI Rewrite that does URL rewriting (search engine friendly URLs in plain speak - and rather similar to mod_rewrite on Apache) failed to start after reconfiguration and wouldn't uninstall or reinstall.
Sorted in the end with some helpdesk support.
Reconfiguring IIS on a live server is always a but nervy!
End result, 20 mins downtime while doing the reconfiguration; then 2 hours or so with the site refusing to serve any pages that used the offending bit of software.
But, on the bright side, this has forced a fair amount of work that'll make migrating the site later this year much easier.
You can wake up now 😉
my orders are to sit here and watch the world go by