Dual Boot Windows XP(Primary) and Windows 7 (Logical Partition)

Here are the steps which work best to recover to Win7 its boot files and the disk space from XP, based on having given them countless times in almost four years. Feel free to bookmark them.

As suggested boot free Partition Wizard bootable CD to rightclick D to Modify>Set to Primary, click OK.

Now rightclick D again to Modify>Set Active, click OK.

Next click on the Win7 HD to highlight it, from Disk tab above click on Rebuild MBR, OK, Apply all steps.

Reboot to see if WIn7 will start. If not boot into the Win7 DVD or System Repair Disk to run Startup Repair - Run up to 3 Separate Times until Win7 starts and holds the System Active flags.

Now that we know Win7 will start on its own from its own partition, you can boot again into PW CD, rightclick on XP to Delete, OK. Then rightclick on C to Resize, slide left border all the way to the left to take up the deleted XP space, OK, Apply both steps. Have your Win7 DVD or REpair CD standing by since sometimes resizing on the boot sector requires repairs.

Kaktussoft is right. There is no problem turning the D partition into a primary. Best is to use the bootable CD of Partition Wizard (last entry on that webpage). Burn that to CD and boot with that CD. Then highlight the D partition, click the Partition tab. The controls are under "Modify".