Delete old partition with Vista on

The Boot flag you're referring to is present because you are booted into that OS at the moment. If you started Vista it would have Boot flag on Vista.

System flag shows us where the boot files are located and they are on the System partition created for that purpose.

Hence you can delete Vista from Disk Mgmt with no problem, recover it's partition space into Win7 using a partition manager like free Partition Wizard bootable CD, or create a New Partition there.

What other partition were you wanting to delete? You cannot delete System partition without first recovering the System boot files into Win7 by marking Active and running Startup Repair up to 3 separate times. System partition likely also contains factory utilities which came with the computer but you may not use, may have only been available in Vista and may have lost their link when you installed Win7.

I would not delete the Recovery partition until you have made the Recovery Disks so you have a way to restore to factory condition if every wanting to sell or gift the computer. If the computer came with Vista, you should be able to make them in Vista under All Programs. It is likely the link to run Factory Recovery from the partition was lost when you installed Win7, but you can try it from boot to see if it cues up to run.

gregrocker said:

What other partition were you wanting to delete? You cannot delete System partition without first recovering the System boot files into Win7 by marking Active and running Startup Repair up to 3 separate times. System partition likely also contains factory utilities which came with the computer but you may not use, may have only been available in Vista and may have lost their link when you installed Win7.

I would not delete the Recovery partition until you have made the Recovery Disks so you have a way to restore to factory condition if ever wanting to sell or gift the computer. If the computer came with Vista, you should be able to make them in Vista under All Programs. It is likely the link to run Factory Recovery from the partition was lost when you installed Win7, but you can try it from boot to see if it cues up to run.

Can you please detail further how to recover the boot files into 7 and I don't plan to sell the computer so is there any risk coming from not having the recovery discs, or is it purely a matter of wanting to sell the PC.

If you don't want the Recovery Partition you can delete it along with OEM, System and Vista, recover the HD space and System boot files into Win7. You will need Partition Wizard bootable CD, and either the Win7 Installation DVD or System Repair Disc - Create.

Back up your files and a Win7 Backup Image so if the operations fail you have a path back: Backup Complete Computer - Create an Image Backup. Otherwise you will need to reinstall.

Boot PW CD, rightclick each partition you want to delete, chose Delete, OK after each.

Now rightclick Win7 partition, select Modify>Set to Active, OK.

Next click on the Win7 HD so it highlights the HD, then from Disk tab choose Rebuild MBR, OK, Apply all steps. Attempt to reboot into Win7.

If Win7 will not start, boot Win7 DVD Repair console or Repair CD to Startup Repair - Run 3 Separate Times
to repair or rewrite the System boot files to Win7 partition.

gregrocker said:

You will need Partition Wizard bootable CD, and either the Win7 Installation DVD or System Repair Disc - Create.
to repair or rewrite the System boot files to Win7 partition.

I have a Windows 7 Professional 32-bit install disc although it is not the one I actually installed this OS with, will it suffice?

As long as the installed Win7 is 32 bit, as the Repair console is bit-version-specific.

Otherwise make a Repair CD in the WIn7 Backup Center. System Repair Disc - Create

My USB is being declined by the system image backup as "an invalid backup device" (yes, its formatted as NTFS.) Can i only do this with dvd as if so, i would never be able to restore as id need the recovery center disc in at the same time

Don't understand your question. Are you attempting to make a backup image so you can do the repartitioning, and WIn7 backup will not save the image to an external USB HD?

If you have a WD or Seagate HD you can use their free Premium Acronis True Image application, or you can use the next best Macrium REflect: Macrium - Image your system
or Paragon Backup free edition.

How much space is required by the built in Windows System Image backup as I have an 8gb usb which is being declined, do i need to go bigger and does the file have to be the only thing on the drive or can other files co-exist with it?

Use a USB external HD, not a flash stick. The image is the size of all used space which is imaged.