I can't boot to Windows after resizing my Mac partition.

Question

So, I recently decided to resize my bootcamp Win7 partition. This is something I have done successfully before, by:
1) Booting into Macintosh
2) Using Disk Utility to decrease the size of the Mac partition (20GB the first time)
3) Booting into Windows
4) Using Mini-Tool Partition Wizard (third-party) to allocate the free space to the Bootcamp partition.
There were a couple issues caused by this the first time around, mainly the fact that Macintosh didn’t recognize the fact that the free space had been taken, and had trouble reading from the Windows partition. However, I could live with that. I have since rebooted to both Mac and Windows several times without problem.
Recently, I decided I needed a bit more space, and so started to follow the above steps, shrinking the Mac partition an additional 15GB. Only when I went to reboot to reallocate the space, the Windows partition didn’t show up as a bootable option. Confused, I booted back to Mac, and the Bootcamp partition was still there, but renamed “disk0s4”, and unmounted. Reparing the disk failed (“Invalid BS_jmpBoot in boot block: 15921e”). The disk wouldn’t mount (not even sure if it was supposed to be mounted earlier, but that’s what it looks like). It also appears grayed-out in the list of drives to the left. It looks like I can create a dmg from the windows drive, although I haven’t done that yet (I will soon).
Any solutions for this? Although I will erase the drive if absolutely necessary, it would be preferred if that wasn’t the first option to try. I had no problems like this the first time I resized the disk.
(My mac partition is running Mavericks, if that is of any relevance)

Answer 1

These steps correct the Partition ID, and the boot ability of the MBR partition that has Windows on it.You can type '?' for help in the following steps where you set the fdisk prompt.
To fix the MBR, in OSX Terminal
sudo fdisk -e /dev/disk0
setpid 4
07
flag 4
p
w
y
q
Please ignore the i386 message that you see in the following. Here is the set of commands in the utility. The utility starts at partition id 1. If you see any other messages, please post back.
sudo fdisk -e /dev/disk0
fdisk: could not open MBR file /usr/standalone/i386/boot0: No such file or directory
Enter 'help' for information
fdisk: 1> ?
  help Command help list
  manual Show entire man page for fdisk
  reinit Re-initialize loaded MBR (to defaults)
  auto Auto-partition the disk with a partition style
  setpid Set the identifier of a given table entry
  disk Edit current drive stats
  edit Edit given table entry
  erase Erase current MBR
  flag Flag given table entry as bootable
  update Update machine code in loaded MBR
  select Select extended partition table entry MBR
  print Print loaded MBR partition table
  write Write loaded MBR to disk
  exit Exit edit of current MBR, without saving changes
  quit Quit edit of current MBR, saving current changes
  abort Abort program without saving current changes
fdisk: 1>