Help Htc one won't factory reset

[Marese73]

I'm in Ireland have a HTC one which was working fine it had some storage issues and fone was slowing down and freezing but nothing major. It was factory reset a couple of times to clear it out. It was my daughters and she left it aside when she got a new fone. We now want to factory reset the fone so my hubby can use it. Fone appears to be working fine with all my daughters apps and accounts logged in etc. When i try to do a factory reset it gets stuck in the bootloader with a locked message. The fone has neva been rooted and everything is stock. None of the options in bootloader work it wont go into recovery or fastest. It will only reboot or power down. Everything else makes it loop and go back to bootloader screen. I thought it might need a software update so ran that and installed the latest update but it's no different. Help pls anyone?

 

[Marese73]

Update on looking at the fone again it seems the update didn't load when it's trying to load the update it just goes back to the bootloader and keeps looping from there