Re: Unpatched PC's ?
This is one of the main reason many NHS computer lag behind in patching, the clinical systems have different dependencies and will react differently to patches, which then have to be tested against the functionality of each system and this has to be documented.
Most hospitals have over 150 clinical systems, so they either wing it and patch, or test rigorously, which means delays which may be compounded if a problem is found and they have to insist/wait/beg for an update from the systems developer.
Contracts are certainly part of the problem though.