June 11, 2007, 3:16 PM — Send your Windows question to Mitch today! | See other Windows tips
The version of the diskpart command included in Windows Vista allows you to shrink partitions to free up space on your hard drive so you can create additional partitions. Unfortunately, the version of diskpart included in Windows XP doesn't include this functionality, so the usual way of shrinking XP partitions is to use a third-party tool like Symantec's Norton PartitionMagic.
If you have a Windows Vista product DVD around however, you can use Vista's version of diskpart to shrink partitions on a computer that has Windows XP installed. To accomplish this bit of magic, do the following:
1. Boot your system from the Vista DVD and select the Repair Your Computer option to enter the Windows Recovery Environment (Windows RE), a recovery platform based on version 2.0 of the Windows Preinstallation Environment (Windows PE) and which replaces the Recovery Console of previous versions of Microsoft Windows.
2. When the Choose A Recovery Tool screen appears, click Command Prompt to open a command prompt window.
3. Type diskpart to enter the diskpart command shell.
4. Use the select volume command to select the partition you want to shrink.
5. Use the shrink command to shrink the partition the desired amount. This command will start by moving data from the end of your partition before shrinking the partition, so be aware that shrinking a large partition can take a long time.
One caveat: I haven't been able to get definitive word from Microsoft that this is a supported scenario for shrinking XP partitions, but everyone I've talked with who has tried it (including those inside Microsoft) have said it worked fine for them and no data was lost. In other words, try this at your own risk.
Finally, for more information about using Vista's system recovery tools see Chapter 30 Configuring Startup and Troubleshooting Startup Issues in the Windows Vista Resource Kit.