Set your phone to manufacture mode plug it in, install drivermax, install unkown drivers ( should appear as COM port icon when searching for the drivers). Install the missing drivers to your computer.
Now go to device manager and instead of seeing four android adapters, it should be 3 and now you should have a COM port labeled as adb or something close to that. Take note of the COM number and go ahead and open up QPST
From their follow the steps given for QPST on the first post in this thread
P.S. - you will need an Spc number to flash the prl to your phone so go to
CheckESNFree.com - The only instant, free, online ESN checker., click metropcs section, and enter the MEID number found under your battery. It will generate the Spc code needed to flash it