[AT&T Samsung Galaxy S II SGH-I777] creepyncrawly:
Can you put the phone into download mode? I would assume the answer is yes if you still get the "connect to kies" message. Following are detailed instructions for getting into download mode.

Download Mode:

There are several ways to put the phone into download mode. You should try all of them that you can before you give up.

Recovery mode:

With the phone off (and not connected to the computer), and battery installed, hold all three buttons, vol- vol+ pwr continuously until the initial boot screen appears the second time.

Download mode:

1. With the phone off and connected to the computer via USB cable, and battery installed, hold all three buttons, vol- vol+ pwr.

2. With the phone off and battery installed, hold vol- and vol+ (but not pwr) while plugging in the USB cable.

3. With the phone off and battery installed, hold vol- (but not vol+ or pwr) while plugging in the USB cable.

4. Attempt each of the above three options with the battery removed from the phone. The computer will supply the power to the phone.

5. Use Android Debug Bridge (adb) which will only work if USB debugging has been already turned on in Developer Options, since you can't boot into the system to turn it on. With the battery installed and the phone connected to the pc via USB cable, use the command "adb reboot download".

6. Use a USB jig. With the battery installed insert the USB jig into the USB connector of the phone. Some have reported that this method works when no other method would work.

If the phone will go into download mode, you will need to use Odin desktop to flash the stock firmware. You should use the latest stock firmware. Go to the Download Repository and download Odin3 v1.85 from the link near the top of the page, and also download the latest stock firmware, "I777UCMD8 Stock Binaries (Android 4.1.2 Jelly Bean)" from near the bottom of the page. It's the next to last item. Download both to your Windows pc, and then follow the detailed instructions below to flash it onto your phone.

How to use stand-alone Odin3 to flash firmware:

Follow and recheck each of the following steps. Do them in order listed, as some steps are dependent on previous steps. Instructions are for Odin3 v1.85. It should work with any version of Odin, but some details, like color of items, may be different.

1.) Open Odin on the Windows Desktop.

2.) Have the USB cable plugged into USB port on the computer, but *Not* plugged in to the phone.

3.) Shut the phone off.

4.) While holding down the vol+ & vol- keys, plug micro-usb plug into phone.

5.) In Odin, you should get the yellow box under where it says ID:COM with the text 0:[COMx], and in the Message area, <ID:0/00x> Added!! where x is some number, usually 1-8.

6.) In Odin, make sure Auto Reboot and F. Reset Time are checked and all other items are not checked.

7.) Click on the PDA button. Browse to the tar file you want to install and select it so its path appears in the text edit box next to the button.

8.) Make sure the check box next to the PDA button is checked.

9.) Click the Start button.

10.) You should see the green progress bar advancing.

11.) When complete, you will get a PASS (or FAIL if unsuccessful).

The phone should boot up normally. If it does not, enter recovery (see instructions in the download mode section) and perform a wipe data/factory reset.