How to dual boot when Windows XP was installed after Windows 7?

"You need to reinstall the boot manager. NTLDR can't boot Windows 7.

Start the Windows 7 install DVD, and choose ""Repair"" and ""Command Prompt"". At the prompt, do a ""bootrec /RebuildBCD"" to write down a new bootloader.

I can't promise that this is going to keep Windows XP in the boot order, but it will restore the ability to boot Windows 7. After that, you can follow any number of articles to get Windows XP back into the boot manager manifest."

"Create Boot Loader

Once installation of XP is successful you can now install the latest Microsoft Updates and drivers. You will undoubtedly notice that the machine is booting directly into XP at this time. This is due to XP writing its bootloader over Windows 7’s. To get both XP and Windows 7 as an option at the boot screen you can use the free utility EasyBCD 1.72 or their new 2.0 Beta.

VistaBootPRO 3.3 (free version) will still work too which you can download here. VistaBootPRO is now called DualBootPRO and is no longer free, it’s $9.95 for a single user license.

After getting the bootloader back you should see both XP and Windows 7 as options in the Windows Boot Manager."

"The problem can be easily solved using Dual-boot Repair tool.

No long tutorials, explanations etc.

Run the tool (obviously in Windows XP), click on ""Automatic Repair"" and confirm.
This will restore booting to Windows 7 by default.

For adding Windows XP to boot configuration data (Windows 7 BCD) you click on ""Fix XP/2003 boot"", select XP \Windows folder and confirm.

That's all ;)"
"The problem can be easily solved using Dual-boot Repair tool.

No long tutorials, explanations etc.

Run the tool (obviously in Windows XP), click on ""Automatic Repair"" and confirm.
This will restore booting to Windows 7 by default.

For adding Windows XP to boot configuration data (Windows 7 BCD) you click on ""Fix XP/2003 boot"", select XP \Windows folder and confirm.

That's all ;)"