After lots of Googling, I gave up on finding a solution online. I decided to delete everything on the phone and jailbreak it (since vanilla WP7 didn't have any backup functions anyways).
I followed this tutorial: forum.xda-developers.com/showpost.php?p=26842868&postcount=46
So thanks to dragonide from XDA Developers.
The tutorial was good, but I'll add some minor details that might be useful:
- Download files from:
DFT Eternity 24 langs Freedom V1 Pearl Edition.7z: http://forum.xda-developers.com/showthread.php?t=1684907
- Turn off your phone and disconnect it from the computer.
- Remove your SIM card.
- Hold volume up and down then press power. continue holding the volume buttons.
- When you see green text on white background with for example version PI39100
..., you are in SPL. It should also say "Serial" about 2/3 of the way down the screen
- Connect to computer with USB. you might have to try different USB ports. Check"Safely Remove Hardware and Eject Media" in the system tray; My phone came up as Titan USB Sync on some ports, in that case flashing failed with 264 and 266 errors. (See http://forum.xda-developers.com/wiki/index.php?title=Elf_RUU_Error_Codes for explanation of errors). When it came up as Qualcomm CDMA Technologies MSM on a port, flashing worked fine.
- Unpack DFT__HSPL_WP7SG1.rar using for example 7-Zip (http://www.7-zip.org/), just right click the file and select open archive.
\DFT_HSPL_WP7SG1\1_SPL205\TITAN\ROMUpdateUtility.exe and follow instructions (takes about 1 min).
- You should see the progress bar in parallel on both the computer and the phone.
- When complete, the phone reboots. Hold the volume buttons until you enter SPL. Notice that it now says "HSPL2.5.160015.3 (137079)" and "Radio-16.23.06.10" (Radio was 17... before flashing on my phone).
\DFT_HSPL_WP7SG1\2_HSPL\DFT_HSPL_WP7SG1_INSTALL.exe and follow instructions (install HSPL) (takes about 1 min).
- Phone will reboot after flashing. When rebooting, hold volume to enter SPL.
- Unpack DFT Eternity 24 langs Freedom V1 Pearl Edition.7z.
\DFT Eternity 24 langs Freedom V1 Pearl Edition\ROMUpdateUtility.exe and follow instructions (takes about 10 min).
- After completing flashing the phone will reboot and probably hang/freeze on boot (just showing the HTC logo). Reboot phone (just hold the power button or remove the battery). Hold volume buttons to enter SPL.
- Unpack RUU_ETERNITY_Radio_Signed_17.5006.08.27_17.08.50.06.7z
\RUU_ETERNITY_Radio_Signed_17.5006.08.27_17.08.50.06\ROMUpdateUtility.exe (takes less than 1 minute).
- After flashing, the phone reboots, hold volume buttons to enter SPL and check that Radio is now 17.5006.08.27
- Turn off the phone (remove the battery).
- Put your SIM card back in.
- Power on the phone like normal and go through the Windows Phone 7 setup process.
- Enjoy jailbroken WP7.
Images of what you should expect to see (sorry for the blur):
Thanks to Sources: