Windows XP Seeking Help to Reformat Sony Vaio VGN NR220E from Windows XP to Vista

I have a Sony Vaio VGN NR220E. I bought it in 2008 with windows vista. It did not came with a reformating CD or anything. I am just assuming that the vista is installed in it. I love my laptop and want to keep it. My brother used it for some years. Now I find my laptop running with XP. In the compter section it says Windows XP Professional 2010. Service pack 3. I want to reformat it. The reason for that is everything seems messed up. If I change a word documents name the document won't open anymore. I wanted to view the partition and clicked on the manage but it seems like I have an MMC problem and I have no idea what that is. I tried the Microsoft support but seems like not helpful for me.
Any help would be greatly appreciated getting the laptop reformatted.