virtualbox.org

Hi all this is my first time using VirtualBox i have mint linux dual boot with windows 7 x64 what i would like to do is have mint as my main OS then run windows 7 that i have installed through virtual box.

i have seen this ( cant post link) How to migrate existing Windows installations to VirtualBox

but when i try cat /dev/sdg | VBoxManage convertfromraw stdin OutPutFile.vdi NUMBEROFBYTES

i get this
OutPutFile.vdi NUMBEROFBYTES
Converting from raw image file="stdin" to file="OutPutFile.vdi"...
Creating dynamic image with size 0 bytes (0MB)...
VBoxManage: error: Cannot create the disk image "OutPutFile.vdi": VERR_INVALID_PARAMETER


what am i doing wrong? also if i do get this to work will i still be able to run windows 7 in dual boot as i currently do?

thanks for any help

See the tutorials forum, "Win7 in both VM and native".