1. Find the OS that you are wanting to downgrade to.

2. Download it to your computer.

3. Run the .exe file and install the OS onto your computer.

4. Do a search for vendor.xml and delete it.

Or go Start/My Computer/C: Drive/Program Files/Common Files/Research In Motion/App Loader and it should be down in the bottom there.

5. Now connect your device to the USB.

6. Start Desktop Manager.

7. Go to Add Applications.

8. A box will pop up giving you the option of downgrading or keeping the same OS.

9. Click the downgraded OS and you are on your way.

Carrier                                                                Region           Network

3 Hong Kong	Asia/Pacific	GSM
A1	Europe	GSM
AIS Thailand	Asia/Pacific	GSM
Aliant Mobility	North America	CDMA
Alltel	North America	CDMA
AT&T	North America	GSM
AT&T	North America	Mobitex
Avea	Europe	GSM
BASE	Europe	GSM
Bell Mobility Inc.	North America	CDMA
Bell Mobilité Inc.	North America	CDMA
Bharti Tele-Ventures Limited	Asia/Pacific	GSM
BT Mobile	Europe	GSM
Cable and Wireless	South America	GSM
Celcom Malaysia	Asia/Pacific	GSM
Centennial Wireless	North America	GSM
China Mobile Peoples Telephone	Asia/Pacific	GSM
Cincinnati Bell	North America	GSM
Claro Brazil	South America	GSM
Claro Peru	South America	GSM
Close Call	North America	CDMA
Comcel	South America	GSM
Comunicaciones Nextel de Mexico	South America	iDEN
CTI	South America	GSM
Dialog Sri Lanka	Asia/Pacific	GSM
Digicel Group	South America	GSM
Dobson Cellular/Cellular One	North America	GSM
E-Plus	Europe	GSM
EarthLink Wireless	North America	GSM
Entel PCS	South America	GSM
Etisalat	Middle East	GSM
Fastlink Jordan	Middle East	GSM
Globe Telecom, Inc.	Asia/Pacific	GSM
Hong Kong CSL Limited	Asia/Pacific	GSM
Hutchison	Asia/Pacific	GSM
Iusacell	South America	CDMA
KPN	Europe	GSM
LUXGSM	Europe	GSM
M1	Asia/Pacific	GSM
Maxis	Asia/Pacific	GSM
Mobistar SA/NV	Europe	GSM
MTN	Africa	GSM
MTS Mobility	North America	CDMA
Nextel Communications Inc.	North America	iDEN
Nextel Comunications Argentina S.A.	South America	iDEN
Nextel del Peru S.A.	South America	iDEN
Nextel Partners	North America	iDEN
NTELOS	North America	CDMA
O2 Ireland	Europe	GSM
O2 UK	Europe	GSM
Optus Mobile Pty Limited	Asia/Pacific	GSM
Orange Belgium Mobistar	Europe	GSM
Orange France	Europe	GSM
Orange Netherlands	Europe	GSM
Orange Poland Centertel PTK	Europe	GSM
Orange Romania	Europe	GSM
Orange Slovakia	Europe	GSM
Orange Spain Amena	Europe	GSM
Orange Switzerland	Europe	GSM
Orange UK	Europe	GSM
Payless Cellular Fantasy	North America	CDMA
PCCW Mobile	Asia/Pacific	GSM
Personal Argentina	South America	GSM
Porta	South America	GSM
Proximus	Europe	GSM
Rogers Wireless Inc.	North America	GSM
SaskTel Mobility	North America	CDMA
SFR Enterprises	Europe	GSM
Singapore Telecom Mobile Pte Ltd	Asia/Pacific	GSM
SMART Communications Inc.	Asia/Pacific	GSM
SmarTone-Vodaphone	Asia/Pacific	GSM
SouthernLINC Wireless	North America	iDEN
Sprint Spectrum L.P.	North America	CDMA
StarHub Ltd.	Asia/Pacific	GSM
SunCom Wireless	North America	GSM
Swisscom Mobile	Europe	GSM
T-Mobile Austria	Europe	GSM
T-Mobile Croatia	Europe	GSM
T-Mobile Czech Republic	Europe	GSM
T-Mobile Germany	Europe	GSM
T-Mobile Hungary	Europe	GSM
T-Mobile Netherlands	Europe	GSM
T-Mobile Poland	Europe	GSM
T-Mobile Slovak Republic	Europe	GSM
T-Mobile United Kingdom	Europe	GSM
T-Mobile USA	North America	GSM
Taiwan Mobile	Asia/Pacific	GSM
TBayTel	North America	CDMA
TDC Mobil	Europe	GSM
Telcel	South America	GSM
Telecomunicaciones Movilnet C.A.	South America	CDMA
Telefonica	South America	GSM
Telefonica Spain	Europe	GSM
Telefonica Venezuela	South America	CDMA
Telenor Sverige AB	Europe	GSM
Telkomsel	Asia/Pacific	GSM
Telstra	Asia/Pacific	CDMA
Telstra	Asia/Pacific	GSM
Telus Mobility	North America	CDMA
Telus Mobility	North America	iDEN
TIM Brazil	South America	GSM
TIM Italy	Europe	GSM
Trigcom	Europe	GSM
True Move	South America	GSM
Turkcell	Middle East	GSM
U.S. Cellular	North America	CDMA
Verizon Wireless	North America	CDMA
VIPnet Croatia	Europe	GSM
Vodacom	Africa	GSM
Vodafone Australia and Fiji	Asia/Pacific	GSM
Vodafone D2	Europe	GSM
Vodafone Egypt	Middle East	GSM
Vodafone Essar Limited	Asia/Pacific	GSM
Vodafone Essar Limited (for Hutch Essar devices)	Asia/Pacific	GSM
Vodafone Germany	Europe	GSM
Vodafone Greece	Europe	GSM
Vodafone Ireland	Europe	GSM
Vodafone Netherlands	Europe	GSM
Vodafone New Zealand	Asia/Pacific	GSM
Vodafone Spain	Europe	GSM
Vodafone UK	Europe	GSM
Wind Hellas	Europe	GSM
XL Indonesia	Asia/Pacific	GSM

[ Last edited by  bb818 at 23-11-2007 18:40 ]

Very helpful post. Ty

thank you very much

Very helpful post. Ty

is there any specific reason why to downgrade the system?

very informative

you may want to use this too for easier option just select the OS you want to install, but ofcourse the OS you want must be installed in your pc.

http://bbsgame.mobi/thread-4362-1-1.html