Formatting a big disk can take long. Is it much longer than it was the last time (assuming you do it the same way)? But formatting isn't really needed to install an OS on the same partition as last time, so I wonder why you do it.
Anyway, I'd start with trying another hard disk. It's rather cheap. If that doesn't make any difference, the next thing to try is another motherboard, I think.
- CPU: Intel Core i5-3470 3.2Ghz Box - BX80637|53470
- RAM1: Kingston HyperX Blu Red DDR3 1600 PC3-12800 4GB CL10 (broken)
- RAM2: Kingston HyperX Fury Blue DDR3 1600MHz PC3-12800 4GB CL10
- MOTHERBOARD: Gigabyte GA-B75M-D3V
- HARD DISK: Seagate Barracuda 7200.14 1TB SATA3-ST1000D
- POWER: Nox Urano SX 500W - NXURSX500
- BOX: ATX Antec GX300 Black USB 3.0
- GRAPHICS: Nvidia PCI Express Asus GeForce GT 730 2GB GDDR5
- READER DVD: Liteon iHAS124-14 SATA OEM - IH
A month ago breaks down one of the RAM 4GB and, after locate and remove, format the hard drive and install Windows 7. A few days ago, turning on the computer, it took over an hour to ask me for the password andI enter had to wait almost another hour to see my desk. After this look at the task manager (Performance tab) where memory was occupied by less than 1 Gb and CPU, if enlarged or diminished the window, he reached peaks of more than 20%. Try to enter an installation DVD again to format the disk but just keeps going and stays slow loading long. Does anyone know where you can be wrong?