How to delete Windows with bootcamp on Mountain Lion 10.8.2

I was trying to delete my Windows 7 Ultimate from my MacbookPro with bootcamp however when I clicked on the bootcamp assistant it said "You must update your boot ROM firmware before using this setup assistant."

So I went on apple website found the right Boot ROM firmware for my macbookPro 13inch which was released on 2010. but then When I opened the downloaded pkg. it says it is not compatible with my computer.

I am trying to delete my windows because when I open it on my mac the screen blacks out after the boot with windows logo popping up saying loading.

What should I do to remove windows?

I could give you the instructions for removing Windows 7 manually, but I suspect there is something else going on. When you installed Windows 7 via the Boot Camp assistant, which version of OS X were you using? Also, when you open the Boot Camp assistant, select "about" and tell us which version of BC it is.

I was using OS X Snow Leopard when I frist installed Windows 7 Ultimate 64-bit on my macbookPro 13inch intel based.

Boot ROM Version: MBP71.0039.B0E

I can't look up the about section when Bootcamp assistant is on it just gives me a warning screen.

My windows7 is pretty much useless now I just want to remove it and install windows 8 that I bought.

I thought so. Usually that error will occur when you installed Windows using an earlier version of OS X and an older version of Boot Camp. See if you can get on the Apple download site and download the latest version of Boot Camp for OS X Mountain Lion 10.8.2. Install it and then try once more to remove Windows. If that doesn't work, we'll go at it with the "brute force" method.

Okay, I tried but it says my bootcamp is already up to date. I think I have to go with the brute force. Can you please tell me how I can brute force delete windows? And I want to know if this is going to cause any problems with my computer, such as empty area in my hardrive which I cannot enter.

First, make a backup of everything that you can. Use Time Machine. I also recommend making a clone of the drive using software such as Carbon Copy Cloner or SuperDuper. You'll need an external hard drive.

Boot to your recovery partition by pressing Command + R upon startup. Once in recovery, select "Disk Utility". Highlight your hard drive on the left and then select the "Partition" tab on the right.

Select the Boot Camp partition, and then press the small minus button at the bottom. Click "apply". That will remove the Boot Camp partition and leave you with unallocated space. Now, select the same partition tab... grab the border line separator between your OS X partition (MacIntosh HD) and the unallocated space. Drag that line until it fills all the unallocated space and it becomes one partition. In other words, your MacIntosh HD partition now fills all the space except for the recovery partition. Click "apply".

Exit recovery and reboot. Hopefully if everything was OK, your MacIntosh HD should be resized to fill the entire hard drive except for the space allocated to the recovery partition. You can proceed from there.