A few years ago I bought an Acer Veriton M2 computer that came with two operating systems installed on the 160 GB hard drive. However, this is not a dual-boot machine. When I turned it on for the first time, I had to decide which operating system I wanted to use, Windows XP or Windows 7 Professional. I picked Windows 7. This means that half of the 160 GB drive (the half allocated to Windows XP) is not available for use. I know that this is true because when I check the properties for the C: drive, the size is shown as 80 GB. Is there a program or utility that I can use to free up the unused partition so that I can make use of it?