Can you tell us exactly what happened or what you did before you kept booting into bootloader?
My friend brought the one mini (AT&T) to me in bootloader, she didn't know how it got there. she said she only pressed the power button and got there. It did have a case on it, and I thought that maybe it had the down volume key stuck and that's how.
In BL (bootloader) I have tried reboot, power down and pressing the power button, recovery, factory reset...and still comes up in BL.
I have this RUU
RUU_M4_UL_JB_50_Cingular_US_1.32.502.3_Radio_1.19.40d.00.14_10.20.40.4408L_release_333483_signed_2
And when I run it on my windows 7 64bit computer its gets to the end page and restarts the phone into fastboot and the phone says fastbootusb but then on my computer it just says waiting for bootloader................ and then ERROR[171]
I have tried different USB cables and front and back usb ports, I have also tried 2 other computers and still says ERROR 171
And yes, I have the drivers for the phone from HTC Sync... IDK what road to take now