Unable to boot - error code 0xc0000225

Yes, I can boot to the Sandisk (Windows 7) with all other drives disconnected.

The USB3 port is on an internal USB3 memory card reader directly connected to the motherboard, so that may be an issue, although your v30 did appear in the Boot Menu when inserted in the USB3, it just didn't load properly unless inserted in the USB2 port.

I booted once more with 17514x64v30, checked DiskGenius and the Sandisk did not show as damaged this time - any thoughts on that?

I'm hoping all is okay - I guess I'll see in the days to come.

I tried the CK iso in the USB3 port and it showed up in the boot menu, but I received a 0xc00000e9 error when I tried to boot from it. I tried a different USB3 port and it booted into the iso but the Y drive did not appear - same as before with v30. It boots fine in the USB2 port.

The 17514v32.iso (the non CK version) was the same as the CK version - it would not boot properly in the USB3 ports. Depending on which USB3 port I used - it either did not appear in the Boot Menu or it booted without the showing the Y drive. It booted fine in the USB2 port.

An update...

I was initially able to boot after DiskGenius fixed the GPT, but was unable to create a new backup system image. I tried with three different programs and they all froze about 20% into the backup. The only way out was a hard boot. The machine was still booting fine - until it wasn't.

I ran chkdsk again on the C drive and it found a couple of bad sectors. I ran DiskGenius again and it also found some bad sectors - when I tried to fix them, the Sandisk died...

So I replaced the Sandisk with a new Samsung SSD, recovered from my backup from a couple years ago, and all seems good. I'm guessing the original boot problem was caused by the Sandisk starting to fail. It would appear that most problems these days are caused by hardware rather than software issues.

thanks again for the help.