I have seen literally hundreds of posts on various forums about people who can’t install Windows 7 because of the very self explenatory error “Setup was unable to create a new system partition or locate an existing system partition. see the Setup log files for more information.”
Most people, including me, don’t know where to find these log files and nothing seems to help. Setting the SATA controller to IDE, AHCI or RAID doesn’t make any difference and it doesn’t seem to matter what kind of drive is being used. It can be an old fashioned hard disk like I have or a super high end SSD über drive, it all makes no difference.
However, I have found a solution that worked for me and might also work for other people, so I thought it would be nice of me to share it with the world. So here we go; chances are that the drives have been previously used and as such they are cluttered with all kinds of stuff that you need to get rid of. Here is a step by step guide on how to get on with it.
1: The first step is to boot the PC using the Windows 7 installation DVD. Then when prompted you select the language you’d like to use. In most cases there is really only 1 option, but just in case the pull down menu is still there.
2: Now you arrive at the point where you would normally choose “install now” but instead you click the “Repair your computer” link at the bottom of the window. At the windows that pops up you choose the option at the top. In the heat of the moment I forgot what either option’s label is, but you will need the first one, trust me.
3: Now you’ll arrive at a menu with several options and here you need to one at the bottom, and of this one I do know the label, “Command prompt”. Even though typing commands isn’t really hot anymore with Windows Vista and 7 these days, it’s a neccesary evil in this case.
4: Once the Command prompt is opened, type “diskpart” without the quotes (type anything without the quotes). Now you type “list disk”. A list of all detected hard disk drives is now displayed. Depending on how many disks you have you have to repeat step 5 and 6 untill you’re finished.
5: type “select disk 1″ (replace 1 with any disk number you still need to do)
6: type “clean” (and don’t forget to press enter after typing a command)
The clean command will remove any pointers to any partitions or volumes that are defined on the disk. Data on the disk will no longer be available after applying this command. Just in case you don’t want to have all of your data destroyed you could skip step 5 and 6 for some disks, just make sure you don’t skip step 5 and 6 for any disk you want to install Windows 7 on. This may also apply to installing Windows Vista, even though I have no idea why anyone would still want to do that.
The disks that I had this problem with had been running in a RAID10 array, so I had to clean them all before I could use any of them to install Windows 7 on. If your disks have always been stand alone it may be sufficient to clean only the disk that you want to install Windows 7 on.
I hope this post helps with overcoming this problem for anyone who might be roaming the net desperately searching for a solution. If you are already discussing this problem on a forum and then stumble upon this post, please don’t hesitate to post a link in your thread! Now do as I said and have fun installing the stubborn bastard that is Windows 7.