I had a problem with the wireless adapter on my PC. When the PC started up it didn't recognise the adapter and I had to pull it out and push it back in for it to recognise it. If I did a restart the PC recognised the adapter.

The problem is how Windows 8 shuts down. If you restart, it does a complete shut down which it needs to do if you are installing or updating software. If you click on shut down, it doesn't fully shut down, but saves a system info file which it uses to do a fast start up. To get it to fully shut down go into Control Panel, System and Security, Power Options, Choose what the power buttons do. Unclick 'Turn on fast start-up' and then 'Save changes'. While you're there you can also select the Hibernate option for your shut down options list.

This solved my adapter problem and may be worth trying for other start up problems people may have in Windows 8.