Windows 7 installation is very much slow and it stops installation in one point . how to fix it?

windows 7 installation is very much slow in my computer. I have tried changing Hard disks but same problem occurred. I have tried resetting BIOS also What can I do to solve this problem. Please help me

Look at the minimum system requirements for Win7 and make sure your machine meets those requirements.

http://windows.microsoft.com/en-us/windows7/products/system-requirements