Partitioning hard drive help?

I had partitioned my hard drive forever ago. I recently wanted to get it all back into one drive. Which is where the problem occurred. I'm running on Windows 7 so I am in Computer Management/Disk Management. i have almost 100g of free space that I want back on my main drive. When I go to create a new simple volume an try an format (NTFS) it fails to format an then I can't extend the volume of my main drive. PLEASE help :(