Port 5000 TCP is used together with port 1900 UDP for UPnP (universal plug and play). It is open on a default Windows XP install.
If you don't use it (and you probably don't) you can easily disable the mentioned ports from listening by opening 'services.msc' from a run box and stop the folowwing services:
'Universal Plug and Play Device Host' &
'SSDP Discovery Service'. Be sure to set them to 'disabled' or 'manual' to prevent them from starting up on a reboot.
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