pop in Disk Management into the search box in the Start menu.
Then right-tap on the drive you want to change and select Change Drive Letter and Paths.
A window pops up showing the drive is being queried for available space.
After it finishes, you want to enter the amount of space to shrink the volume by.
Remember that the size you select is in MB so, like in this example.
40,000MB is equal to 40GB.
The minimum to go with on a Vista install should be 20GB.
You’ll also want to plan for how much space you want on the Windows 7 partition as well.
When you have the amount of space entered in, nudge the Shrink button.
Right-tap on the Unallocated space select New Simple Volume.
That starts up the New Simple Volume Wizard that is a straight forward process.
Then in the Format Partition screen it’s possible for you to leave the default tweaks how they are.
One thing you might want to change though, is the Volume label.
You will also see it listed in My Computer.
Now everything looks good to go.
You want to boot from the Vista disc that you have.
Most computers will let you choose the boot option by hitting the F8 or F12 key during startup.
you could also go into the computer BIOS setting and select your CD/DVD drive as the first boot gear.
And kick off the installation as if you were doing a clean install of Vista.
If you want to create a Windows 7 / XP dual boot system we have aguide for that too.
