Stuck in boot screen, computer wont recognize phone in fastboot USB..

I have a sprint CDMA evo 3d. Somehow I bricked my evo 3d. I had an older version of viperRom and tried to install the newest version and its bricked , just locks up at the HTC start screen. Tried to revert back to the older version and still bricked. At this point I'm just trying to unroot and go back to stock in hopes of that working.

I think its an issue with the drivers and my PC.

I'm on hboot 1.5 and its unlocked. I have windows 8 (but also tried this on my win 7 pc) ..I downloaded HTC sync and uninstalled. I have SDK tools with all the updates.
I go into fastboot on the phone, it shows fastboot USB and then my PC recognizes the phone but tells me there's a problem with the driver. I manually select an android ADB driver I have (I have win 8 in the mode that does accept unsigned drivers), it says everything is ok. But then a few seconds later the phone 'disconnects' and doesnt show 'fastboot usb' any more and says there was a problem.
Anyone have a driver I should try or any other suggestions?

johnnyslt said:

Update Windows to 8.1 and the problem should be fixed. There were some problems with Windows 8 USB drivers.

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I have windows 8.1 , but also tried this on my windows 7 computer. I had installed the rom a long time ago, if i recall correctly I had to change a setting on the phone to enable adb to recognize the phone... But obviously that is not possible. Any suggestions?

leetree2001 said:

Do u have custom recovery?

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TWRP recovery v1.0.3

leetree2001 said:

If u can get into it from bootloader, volume - & power
,u can just flash another from.

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I can get into bootloader / fastboot / recovery. But something is messed up. I've tried flashing new ROMs...the flash is successful but it wont boot...still gets stuck on the HTC boot screen

hossman said:

You need to make sure dumlok is on or flash boot.IMG through fastboot

Just read you cant connect to PC
....try uninstalling HTC sync and updating drivers, reboot....hopefully that helps

Sent from my Evo 3D CDMA using xda app-developers app

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I tried that, but I had trouble finding drivers. Anyone have a link for up to date drivers for the evo 3d that work on win 8.1?