For deleting from the command line, something you may want to try is to run cmd as an admin. Easiest way to do this is to type 'cmd' into the start menu search box and hit Ctrl + Shift + Enter.
Thumbnails may have been disabled somehow, to check open up 'folder options' in the control panel, select the view tab and the first option should not be checked. Explorer not loading the Computer folder is rather odd, can't say that I have seen that before so, but I will think about it and I may come up with something other then a repair install or restoring a previous backup.
Could still be a hard drive problem even if it is new, it's not unheard of for computers to arrive with broken parts.