My BootDevicesInitTime is 339935ms

My Boot-up time is almost 6 minutes.

The longest event during boot, as reported by Event Viewer ( Error 100 )
is BootDevicesInitTime with a value of 339935ms.

How can I find out exactly which Boot Device is causing the trouble ?

cluberti said:

If you can, get a boot trace using this tutorial

Did that, but it didn't do much to identify the culprit.

It seems that Windows 7 randomly loses a partition every so often
and that causes the long boot-up time, as the OS tries to identify
the existing partitions.

When I assign the partition its letter, everything's OK again...until the next time.

Clarifying, the partition isn't "lost".

Somehow, the drive letter gets unassigned, i.e., the partition is fine,
it's just that there's no drive letter associated with it.

I ran a Samsung ES Tools check on both hard drives (500GB & 1TB)
and the test reported that both drives are fine.

That jives with the problem being an OS problem (partition table)
and not a hardware problem, since if it was a hardware problem,
the partition(s) would be totally lost, right ?

I'm stumped by this. Any other ideas ?