During reliability upgrades to its .Net messenger services, Microsoft technicians incorrectly configured the routers they were installing which left the service unavailable for 5 hours on Monday from 9am to 2pm EST.
The effect the outage will have on Microsoft's reputation remains to be seen. Some analysts believe it could not have come at a worse time as MS work to convince corporate customers of the reliability of its IM network for business use.
Others have said there will be little if any impact to Microsoft. Michael Sampson with Ferris Research said; "It's certainly not good for Microsoft. If [users] were paying for it, they would be a bit more annoyed". http://www.cnn.com/2003/TECH/biztech/01/08/techweb.microsoft.outage1/index.html