Windows XP

Windows XP is still my OS of choice, however, there are a few niggles that that I really hate: Say if I connect a certain peripheral via USB, then I remove that and plug it into a different USB slot, Windows XP does not recognise the device, and it asks for the driver CD again, and it would not give up until you plug the device into the same USB slot, or re-install the driver.

When you first install XP, its Network support is very flaky, and even though the drivers are correctly installed, and it shows that there is a connection, but trying to connect to an always on Broadband connection is almost always results in failure with an IP address conflict or Windows unable to acquire network address. I usually  install an external Wireless Network Card (USB), connect to my network and download the latest patches - these usually fix everything.

Something else, and this is endemic in all versions of Windows, say you try to copy a few hundred files across from one place to another, and Windows encounter's a problem, half way through, it will just stop, leaving you in limbo, instead of copying the files with no problem, while ignoring others...