

Please let me know if you need further details which can help fix this issue.

the partition remained as an allocated space.

I thought deleting the C partition will allow me to install but it didn't. then the "the selected disk has an MBR partition table." error appeared. I didn't want to assume it's hard drive failure right away so I downloaded a bootable Windows 7 to my flash drive, tried to install it to my C parition of about 40gb. To give you some background as to what happened, it started with my PC acting up like unable to load application as simple as notepad and sticky notes without having to wait minutes.
