ASRock Forums : Z77 Extreme 4 boot problem https://forum.asrock.com/ Copyright (c) 2006-2013 Web Wiz Forums - All Rights Reserved. Fri, 29 May 2026 05:36:33 +0000 Wed, 11 Nov 2015 20:08:42 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.04 360 https://forum.asrock.com/RSS_post_feed.asp?TID=1209 <![CDATA[ASRock Forums]]> https://forum.asrock.com/forum_images/web_wiz_forums_black.png https://forum.asrock.com/ <![CDATA[Z77 Extreme 4 boot problem : I&#039;m getting a blue screen...]]> https://forum.asrock.com/forum_posts.asp?TID=1209&PID=5565&title=z77-extreme-4-boot-problem#5565 Author: MIG
Subject: 1209
Posted: 11 Nov 2015 at 8:08pm

I'm getting a blue screen "OS drive unavailable" at startup. I can restart / reset any number of times, and still get this error. But if I use DEL to open the BIOS, then exit without saving, the system boots and runs normally.

I set up the system some years ago with a single SSD for the OS and several SATA hard drives for data. The boot loader is on one of the SATA drives, and the SSD contains the OS. All has been working perfectly, even after a Windows 10 upgrade. Then last week I got the blue screen on boot, and I now have to enter and exit the BIOS to start the system every time.  I haven't made any hardware or software changes recently.

It looks as if the SSD isn't visible on startup.  But why does opening and closing the BIOS make it appear?

Any thoughts would be much appreciated.
]]> Wed, 11 Nov 2015 20:08:42 +0000 https://forum.asrock.com/forum_posts.asp?TID=1209&PID=5565&title=z77-extreme-4-boot-problem#5565