I need some help ASAP as I need to launch this site by Friday.  I have no idea what I did - the only files I was touching was a skin being used for the new homepage and a tiny part of the site style sheet.  When I left work, everything was working fine.  I remoted in from home, did some minor text editing, worked on the homepage skin a bit and left for a bit.  When I came back, the admin menus had vanished - or had gone from white to a dark red.  The admin pages are now aligned vertically instead of horizontally as they had been and,  worst of all, I can't access any of the module controls on any page to modify any of the content on the site. Instead of the flyout menus I've been getting, now I have nothing.

I've tried to restore the site files from a backup made last night but that didn't help.  And I doubt that doing an upgrade from my current 6.00 will do anything either.  I've seen references to something wrong with a skin but I wasn't doing anything to any of the default  skins and I've since changed everything back to where it was last night with no effect.  

In short, I have no idea what I did to cause this to happen and no idea what to do about it, short of restoring the site from a code and data backup from yesterday.  If anybody has any suggestions or recommendations, I would be most appreciative.

More info.  It definitely looks like scripts stopped loading all of a sudden.  Checking with Chrome and I'm seeing hoverIntent.js, initWidgets.js and some others showing as not being loaded.

I did all that and did a database restore this morning with the same results.  In looking at the Network monitor in IE9, I'm getting a lot of errors pertaining to 'jQuery' is undefined and Object expected because it can't find the file.  Most curiously, when I look at the line where the errors start occurring in admin.aspx, jQuery is loading as: 

<script type="text/javascript" src="/Resources/Shared/Scripts/jquery/jquery.min.js?jQuery is not Installed." ></script>

In host settings, JQuery is shown as not being installed - I have the box checked to use the hosted versions but that isn't helping.