Fix error

Error:” The following issues are preventing Windows from upgrading. Cancel the upgrade, complete each task, and then restart the upgrade to continue.

There is not enough free space on partition (drive:). A total of space_size megabytes (MB) of free disk space is required. Try Disk Cleanup, or moving files to an external location such as a CD, DVD, or external hard drive, and then restart the installation.”
This problem occurs when the virtual memory paging file is reduced below the recommended size. Windows upgrade requires that the page file be the recommended size, and it requires that sufficient space be available on the drive to accommodate a default sized page file. By default, Windows stores the paging file on the system volume. Therefore, there is insufficient free space on the system volume when you try to upgrade to Windows 7.

To resolve this problem, we have two options:

Option 1: Free up space on the system volume
Use Disk Cleanup, or try to move files to an external location such as a CD, DVD, or external hard disk drive. Then, restart the installation. Make sure that required free space is available on the system drive.

To free up space on your hard disk, Disk Cleanup finds and then removes temporary files on your computer that you decide you no longer need. If you have more than one drive or partition on your computer, you are prompted to select the drive that you want Disk Cleanup to clean.

Steps to start Disk Cleanup:
Step 1: Go to Start
Step 2: Go to All Programs -> Accessories -> System Tools-> Disk Cleanup

Option 2: Move the paging file to another volume
Step 1: Log on to the computer as Administrator.
Step 2: Go to Start, right-click Computer and then click Advanced system settings.
Step 3: In the System Properties dialog box, click the Advanced tab, and then click Settings under Performance.
Step 4: In the Performance Options dialog box, click the Advanced tab, and then click Change.
Step 5: Click to clear the Automatically manage paging file size for all drives check box.
Step 6: In the Drive [Volume Label] list, click a drive other than the one on which Windows is installed (typically, this is drive C). Under Total paging file size for all drives, note the value that is displayed next to Recommended.
Step 7: Check the Custom size box, and then type the recommended value in the Initial size (MB) box.
Step 8: Type the maximum size that you want to allow for paging in the Maximum size (MB) box, and then click Set.
Step 9: In the Drive [Volume Label] list, click the drive on which Windows is installed, click to select the No paging file check box, and then click Set.
Step 10: Click Yes when you are prompted.
Step 11: Click OK, and then restart the computer.