There are plenty of reports of both Windows XP and Windows 2003 server systems stalling when running windows update (WU/MU). In some cases, they say that if you wait several hours, or perhaps overnight, the situation will resolve itself.
The long delay is (apparently) due to an IE detection process.
So, what does one do?
The suggestion is to download and manually install the December 10, 2013 Cumulative Security Update for Internet Explorer (MS13-097 / KB2898785). By installing it manually, you remove that detection from the workstation.