Regardless if you're installing Windows 7 on a new hard drive, previous installation of Windows or just wish to clean a drive Windows 7 makes this task a fairly simple step.
Log into Windows 7 and wait for your desktop to finish loading. Once everything is loaded click on the round windows icon in the lower left-hand corner to pull up available programs and options. This is what used to be the "Start" button in previous Windows versions.
Note: You will need Administrator access to perform the format so make sure you're logged in under an administrator account before proceeding. Also, this is meant for separate partitions or additional hard drives you may have attached to your PC, not your primary partition/hard drive Windows 7 is installed on.
Click on "All Programs" at the bottom of the list. When that opens up select "Administrative Tools". That will open up and you should see several programs. You'll want to select the program called "Computer Management". Wait for the program to open up and then continue to the next step.
Now that the Computer Management Program is open you'll see many menu items on the left hand side. You'll want to open the "Storage" menu item if it isn't already and then left click on "Disk Management". Left clicking will open up the Disk Management options. Note: It may take a few seconds for this window to display depending on how many partitions/drives you have for it to load.
There are two main sections to the Disk Management Window: Top view which is a details view of all partitions/hard drives, then a logical view that shows each individual hard disk and the partitions that exist on it. Also, any size in the bottom that shows "Unallocated" means it is unpartitioned space and will need to be partitioned first before formatting. To make a new partition on an Unallocated space right click on the box that shows the Unallocated space and select "New Simple Volume". A wizard will pop up and walk you through the rest of the process.
You'll need to locate the partition to format (if it's new or unpartitioned it will not have a drive letter if it has not been formatted yet). It's very important to make sure you've backed up any files on the partition you are about to format if it was in use previously. Formatting the drive will erase all files from the drive.
Note: Disk 0 may not be your primary Windows 7 installation. Make sure you know what drive letter your main Windows installation is on and do not partition or mess with that drive as you may corrupt your Operating System and lose important files.
Now that you've selected your drive or partitioned space you're ready to format the drive/space. There are a few options when formatting to consider.
Right click on the drive/space to partition and select "Format". A new window will pop up with a few options. For Volume Label replace "New Volume" with whatever you'd like to call the drive ex: Data, Backup, Music, Movies etc. I generally call the drive whatever I'm saving there for ease of finding/organizing files.
Next, you'll select the File System. The default is NTFS which is the default for Windows since Windows 2000. There may be a need for you to use FAT but I only suggest this for advanced users as it is often a space hog and not as secure as an NTFS formatted drive. Going into the differences between NTFS and FAT file formatting is not in the scope of this document. I'll include links for those more interested on the topic.
For Allocation unit size keep the default.
Lastly, you can either keep "Perform a quick format" checked or "uncheck" the option. The differences are as follows:
Quick Format: Removes files but does not check for bad sectors on the hard drive. Not recommended if you've been having issues with a drive. A Full Regular Format: (Quick format unchecked) - This also removes all files but also checks for any bad sectors on the hard drive. The scanning for bad sectors is what takes a long time but is well worth it if your drive has been having read/write issues or acting up in general.
After setting the type of format you want click "Ok". You'll get a message reminding you that the format will erase all data and if you want to continue. Click "Ok" to continue.
Depending upon the type of format you selected and the size of the drive/partition it can take anywhere from a few minutes to several hours. You will not get any notice when it's complete. This completes the walkthough happy formatting and good luck!