Here is the most interesting thing I've noticed since the problems started:

If I go into a control panel/system module (in this case the Resource Monitor) that has a "Check Online" type option, Firefox (my default browser) opens right up without a problem.

But if I just start Firefox from any shortcuts (start menu, desktop, etc), the Firefox process starts up (and the start menu icon starts glowing) only to end without notice a few seconds later.

Possibly related: If I start up in Safe-Mode (w/o Networking, but haven't tried with yet), I can start up FF or Chrome just fine, but if I attempt to open Chrome normally, I get a permissions error.

Opera and Safari seem to be okay (mostly). Safari crashes when I try to download any files.

---

All of the above leads me to believe that some (but clearly not all) core files have messed up permissions. Or rather, that I no longer have permission. System still does, based on Firefox opening without fail when the system initiates it.

I've run MS Forefront once in normal mode, Malwarebytes twice in normal mode and once in safe-mode. One trojan found and deleted, but the problem persists.

Two other things worth mentioning:

I accidentally duplicated my library...

I thought I'd try to add the "Internet" folder to my start menu, next to music and downloads.

The first advanced thing I tried was "create new library". I clearly misunderstood what this means. I thought it was a way to add virtual folders to the library (which I thought, in turn, would allow me to choose it as a link on the start menu), but instead it recreated my already existing user folder, AppData and all. I didn't notice this until today.

Then I tried setting permissions for my User folder to full control, recursively...

Confused but not giving up,I thought I could maybe create a shortcut to the NetHood folder manually, but instead got hit with an access denied error. So I tried to change the permission levels for all sub-folders to my user folder so that I had full control. I got several access denied errors along the way.

---

At this point I gave up, went out, ended up caught in the rain and stuck on a friend's couch and showing up late for work the next day. Thanks for nothing, Microsoft.

When I finally got home today (20 hours later), I noticed that Firefox was acting really strange. I tried opening Chrome to see if the problem was client side or server side, and instead got the above-mentioned "you don't have permission to open this program" alert.

And I think that's the whole story.

Oh, I also did a system restore, but not chose a point from this morning (an auto update), and it worked but the problem wasn't fixed. And then all the earlier restore points were gone.

So the questions are:

a) is there a way to set the admin and user privs back to "default"?

b) would this, in anyone's expert opinion, fix the problems I'm having?

c) how come being logged in as an admin isn't the same as being logged in with admin privs? It seems that half the time I have to do run as admin for fairy standard things because i'm being treated as me-theuser and not me-theadmin.

Thanks for reading.