Hello can I download and install Rim os from other providers?
I have a nextel phone 7100i can i make it think its a t-moble 7100t?

I have t-moble service by the way...

Wirelessly posted (Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0) BlackBerry8703e/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/105)

No it has to be iden for you ie telus just download witch everone is the newest delete vendor.xml and your good to go

Can i install the tmoblie software first copy the vendor.xml uninstall the tmoblie and install the nextel one and change the vendor.xml to the tmoblie one?

The only reason i want to do this is so it will setup the internet connection for me so it knows where to go.

You can not make an 7100i work on T-Mobile. No how, no way.

Even if i get the Sim unlocked?

No. The 7100i uses the iDen network and is not compatible with the T-Mobile network. It is not a software/unlock/whatever issue. It simply can not be done. The 7100i can only be used on iDen network like Nextel. It can not be used on T-Mobile.

hmmm ok can i use it to make phone calls if i unlock the sim? on tmoblie sim of coures..

No.
Forget the words SIM and unlock for now.
You can not use the 7100i on ANY OTHER NETWORK besides Nextel (and their associates), which does not include T-Mobile.
The phone can not be used on T-Mobile.
You can not modify the phone to use it on T-Mobile.

It's a frequency thing. It's kinda like saying, if I change the numbers on my AM radio, can I tune in FM stations?

ok so that means i need to sell this one and get a 7100t then