Tom,
Thanks for filling in the gaps. Based on my first upgrade experience to Windows7 (from XP), I'm hopeful that your inability to rename/delete/move is a simple permissions problem and easily rectified.
The missing presets thing is a bit more of a story. The way LR works in relation to the storing of presets is as follows:
By default the presets are stored in the user settings folder (AppData in Windows7) on the same drive as the OS. Any presets that the user then creates, be it Metadata, Export, Develop get stored in the relevant set of sub-folders under the folder Roaming>Adobe>Lightroom. If, as you do, you use the SAME catalog and picture folders on one EHD and then share that environment on 2 or more computers, each with its own copy of the LR installation, then you would need to synchronise the settings across those computers, which generally can only be done by manual copies. Not an insurmountable problem, but definitely something the user would need to be aware of.
And so we come to the "Store presets with catalog" function, which on the surface gets around the problem of keeping the presets in sync, yes? Well not really.....the first time you change your preferences to select this option all that happens is that Lightroom will create a folder called Lightroom Settings in the same folder that contains the catalog....but it does NOT import the previously user-created presets from the User area. So the Lightroom Settings preset folders are initially empty, which gives the effect of existing presets 'disappearing' until such time as you manually copy your user presets into the relevant sub-folders. The problem is further exacerbated if you use multiple catalogs as "Store presets with catalog" is a general LR preference, NOT a catalog preference....so for every catalog, LR will create another set of (initially blank) Lightroom Settings folders and it will be down to the user to consolidate the presets as appropriate.
In your situation, if you are using the one catalog but shared across 2 or 3 computers then it makes perfect sense to have the presets stored with the catalog (BUT you MUST ensure that the "Store presets with catalog" option is checked on ALL of the computers). You just have to ensure that you have your presets properly consolidated into that Lightroom Settings folder which you should find alongside the catalog.....for now it sounds as if on the Windows 7 PC you have Lightroom looking in the wrong place for the presets, so you need to simply check that setting on each computer, get it the same on each, and make sure your actual presets are copied into the appropriate sub-folder in the Lightroom Settings folder alongside the catalog.
I really do hope that makes sense.....it might be worth having a look at this thread for some further discussion on this issue:
http://www.lightroomqueen.com/community/index.php?topic=9447.msg63646#msg63646