I've used Boot Camp to install Windows 8 on my Air some time ago and I was trying to remove the windows partition to restore some space. Except Boot Camp gives me a warning saying "The startup disk cannot be partitioned or restored to a single partition."
This is what my disk setup looks like.
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *121.3 GB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_HFS Macintosh HD 80.0 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
4: Microsoft Reserved 134.2 MB disk0s4
5: Microsoft Basic Data BOOTCAMP 40.3 GB disk0s5
I'm pretty sure the Microsoft Reserved (disk0s4) partition is giving me the problem right now. I can't mount it or do repair on it from disk utility.
I've called Apple support to get help but they spent 10 minute explaining 10 different ways I can pay them to receive help.