Will an ordinary T-Mobile SIM card designed for a mobile phone work in a

If the USB dongle is free from network restriction, it would definitely work with a T-mobile SIM card. If the USB dongle is locked to some other network, you need to unlock it in prior. You can unlock a modem safer and easier using unlock code. You can get the accurate unlock code from Unlock-Zone.com at affordable cost. Once you have received the unlock code, you can visit MobileUnlockGuide.com to get the free unlocking guide. Good luck.