Use this software
http://www.4shared.com/file/58R7aH5j/dc_unlock.html
Instructions:
1. Remove the current SIM which provided by your current Operator and Insert a SIM of a another network.
2. Connect the ZTE dongle to your pc and wait for the Mobile Partner /Mobile Connect software to run. (It might ask for an unlock code. Ignore it.)
3. Close and Exit form the Mobile partner/connect software.
4. Double click and Run the dccrap.exe
5. Select ZTE datacards form the Manufacturer list.
6. Do not select the model. keep it as AUTO SELECT (RECOMMENDED)
7. Click on the Detect Data Card Button. (Magnify Glass Icon)
8. If card is detected by dccrap you'll get all of the information about the card.
(Locked cards will display a msg "NETWORK LOCK" or something similar)
9. Click and Expand Unlocking Tab on the top right side.
10. Click Unlock.
Your data card will be unlocked by dccrap!
Enjoy