My Windows7 password on startup screen doesn't work anymore.

[Annyb33]

My acer aspire 7741z won't let me log in on startup!! Also I keep getting an error message sayiing 0xc000000f and the boot selection failed because a required device is inaccessible!! Help

 

[webworkings]

There is a few different reasons this could occur, including your hard drive failing.

Here is a long list of info on how to walk through the different things that could be the cause. https://neosmart.net/wiki/0xc000000f-error-read-boot-configuration-data/