Open "My Computer" and double click on "Local Disk C:". Right click on each of the following folders and choose "Delete"...accept the change in each case:
Note: If these folders don't want to delete, you may have to open the folder and delete a few of the folders within...then try to delete it again. They will eventually go.
Then open the boot.ini file again. In the notepad window, click "File", choose "Save As" and save a copy of the boot.ini to your desktop...name this file bootold
In the open boot.ini, remove the lines in red below. Click "File" on the toolbar again, and choose "Save".
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetectmulti(0)disk(0)rdisk(0)partition(1)\WINDOWS.2="Microsoft Windows XP Professional" /fastdetectmulti(0)disk(0)rdisk(0)partition(1)\WINDOWS.1="Microsoft Windows XP Professional" /fastdetect
Close all open windows and reboot. The machine should boot directly to your default installation and you will have regained several GB of free space on the drive.
If everything is working as it should, you can delete the bootold file you saved to the desktop.