There are multiple ways to flash your drive either in windows, in dos both using an xbox360 as power or using the connectivity kit in windows or dos.
I ran into slowing down or freezing problems trying to use anything in windows. Thats Jungleflasher or dosflash32.
So i used the boot disk method made with iprep. And i tell you it was so easy once i worked it out.
So firstly your going to need a few things.
A supported chipset, i had to buy a Via 6421 off of ebay looks like this:
Then you may need the proper drivers if flashing from windows. You may get a cd with the card but these generally install 3249 drivers you want 6421 controller which are these:
http://hotfile.com/dl/5699190/7bb3cf7/via_raid_v530c.zip.html
Now you need to grab iprep V008.8:
http://hotfile.com/dl/5699258/fd42770/iPrep_v008.8.rar.html
Install iprep and navigate to its install folder and goto resources (typically c:\program files\iprep\Resources) and put this file ixdef.xml in there. this currently supports upto 1.51:
http://hotfile.com/dl/5699402/579512f/ixDef.xml.html
You'll need this firmware file for your benq drive:
http://hotfile.com/dl/5699574/2086c27/ix151-benq.bin.html
You need a floppy or a usb drive if you can boot from usb. i couldnt so had to use a floppy.
So load up iprep
Load benq firmware
Select your sata controller..it should be VIA VT6421 RAID Controller if you have the same card as i have.
Select com port. either 1 or 2
Select your target device mine was A:\ using a floppy. Yours should be the same if using flopp. If your using usb device selct the path.
Tick the box "format" (Floppy only i think)
Tick the box "include batch files"
Click start and let it build your floppy/USB drive
Now that its built your bootable disk. turn your computer off.Unplug any disk drives and cd/dvd drives (not necessary but to avoid flashing the wrong object) and Hook up your xbox drive to sata DO NOT TURN THE XBOX360 ON YET. (if you have the same card as me your will most likely have to use the same port as me circled in red)
Start up your computer and load bios changing settings to have floppy or USB to boot first. Save settings and restart with your bootable disk in.
You will get a screen saying enter dben ******* *****
So do so. ******* ***** is your serial found on the back of your case above the power
Now a disclaimer telling you what to do will come up. TURN YOUR XBOX360 ON NOW.
Press any key to continue.
It will check your sata ports you should have your drive picked up. it should tell you to unlock the drive by:
ejecting
Pull the sata power cable from the drive
Close the tray half way
Plug back the sata power cable
Enter Y when ready to proceed.
It will ask you which atapi number it is. mine was 4 so i entered 4. Your lookin for the device with "ATAPI PDBS VAD6038-64930C" or something similar.
It will now ask you whether to read erase or write
enter "r"
Enter firmware backup file: BenOFW.bin
It will now read 4 blocks (0-3) and save a file.
It will say finished now as i was using a floppy i had to transfer the "BenOFW.bin of off my floppy as its not big enough but if using a usb drive you should be ok"
it will load firmtool and get your key and prepare for writing
click any key to continue
Now if you have to type fben ******* *****
It will now create a file, if you get a "Insufficient disk space" message your most likely using a floppy, and didnt move your "benOFW.bin" off
You should see the same steps as reading. except you tell it w to write and the file name is BenCFW.bin.
It should erase automatically
Flash 4 blocks (blocks 0 - 3)
And finish. you can now turn it off and remove your xbox drive.
Disclaimer: these steps are done at your own risk, i will not be held responsible for any errors you may cause or may occur. content due to their respective owners.