I've used a new SanDisk Extreme USB thumb drive to deploy my huge Configmgr Task Sequence as a standalone Media. When booting from it i see the Windows 8 PE Logo, a dialog with "Initializing hardware devices" and afterwards i get the following error: "Unable to read task sequence configuration disk". In the SMSTS.log file i regogniced the following entry: "Booted from fixed disk".
I've read a lot of posts pointing to missing Network Drivers, usage of USB 3.0 slots, etc. which did not help me.
In my case the problem is because my USB removable Sticks is discovered as a fixed Hard Disk and indeed in Windows Explorer it shows up as a normal hard disk.
Unfortunately fixed disks are not supported to be used as standalone Media in ConfigMgr. All vendors are fored to create removable sticks as fixed Disks as they will not get any Windows 8 certification from Microsoft without. I'm really disappointed about the communication which is (not) taking place between the Windows and ConfigMgr Team at Microsoft.
The only solution right now is to buy other USB Sticks which are discovered as removable, thumb drives. The only problem is, i have no idea which sticks can be used and which not...