Windows 8 install issue

Hello,

I have been trying to install Windows 8 on this computer on an upgrade from Windows 7 to Windows 8 (keeping all files and settings and apps):
Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows 7 Professional, Service Pack 1, 64 bit
Processor: AMD Phenom(tm) II X4 945 Processor, AMD64 Family 16 Model 4 Stepping 3
Processor Count: 4
RAM: 10238 Mb
Graphics Card: NVIDIA GeForce GTX 650 Ti, -2048 Mb
Hard Drives: C: Total - 120093 MB, Free - 41774 MB; D: Total - 476806 MB, Free - 77180 MB; G: Total - 182817 MB, Free - 122362 MB;
Motherboard: Gigabyte Technology Co., Ltd., M52L-S3P
Antivirus: Bitdefender Antivirus, Updated and Enabled


Unfortunately, when it boots up during the second half of setup, the graphics are glitching and there are shadow problems! When the glitched mess goes away, there is just a black screen -- no mouse -- and no signal according to my monitor. When I did a hard reset, it reverted back to my previous Windows 7 installation which is where I am now! To install Windows 8, I am using a iso file that was created by the Windows 8 Upgrade Assistant.

Please do help.