Windows – Mac OS X 10.9.3 Bootcamp: “No bootable devices.”

Is the partition seen when you open the Startup Disk preference pane under System Preferences?

Chances are one of two things has happened:

• You've damaged your hybrid MBR -- Macs that dual-boot OS X and Windows 7 almost always use a hybrid MBR, which is an ugly and dangerous (see the next possibility) hack. If resizing your partitions has damaged the hybrid MBR, or replaced it with a standard protective MBR, you'll be unable to boot in BIOS mode. The solution is simple: Create a fresh hybrid MBR. You can do this with gdisk (see the previous link) or with the gptsync tool that comes with rEFIt and rEFInd.
• You've moved or damaged your Windows partition -- If you moved the start point of the Windows partition, it will no longer boot. If you've damaged the Windows partition, it might no longer boot. These are both possibilities if you've been adjusting partitions. Note also that hybrid MBRs make such adjustments particularly tricky. You said you used OS X to do the changes, which is good; making such changes in Windows is almost certain to do serious damage to your partition table and leave the disk in an inconsistent state that can lead to ever-worsening problems. In any event, repairing a damaged boot caused by a moved Windows partition will require the use of Windows emergency recovery tools. If you've damaged your partition table, I recommend you back up everything on the disk and then dig in for a very tough recovery session, because fixing that sort of damage won't be easy. This site's format doesn't lend itself to the sort of back-and-forth interactive help you'll need to repair that sort of damage.

My suspicion is that you're just looking at a damaged hybrid MBR, but I can't be positive of that. Try reading the page to which I linked and examining your disk layout to figure out what's going on.