First, it sounds like you tried to update your firmware in response to your problem, but this was dangerous overkill. Your problem was NOT firmware-related. With any luck no harm will come of that; the process will either error out (for which it's well overdue if it's been sitting there for 4-5 hours) or rebooting now will cause the firmware to start normally (even if you can't currently boot an OS). If your computer doesn't go through the normal startup motions (the stuff it did even before you got the GRUB rescue prompt) when you restart it, then you'll probably need to either send it to the manufacturer or enlist hands-on local help from a super-geek to get it working.
Second, your problem is caused by the fact that you deleted the Ubuntu partition, but the Ubuntu boot loader (GRUB) used to reside partially on that partition. Because Ubuntu installed GRUB to take over boot duties, when you deleted the Ubuntu partition, you rendered the computer unbootable. The solution is to re-install the Windows boot loader to the MBR. This process is covered here, among many other places. I'm not an expert on Windows repairs, so I can't help further than this; but there must be hundreds, if not thousands, of Web pages devoted to this subject, so a Web search will turn up more help.