Once you have installed W7, what does the device manager show under Display Adapter?? Is there a yellow triangle?? Does it show the correct driver?? Have you tried installing the drivers in XP compatibility mode??
See Brinks tutorial on compatibility mode -=> here
My Computer
At a glance
64-bit Windows 8.1 ProCore(TM) i5 CPU 4330 Haswell @ 3.20GHz12.00 GBIntel(R) HD Graphics
Computer type
PC/Desktop
Computer Manufacturer/Model Number
LENOVO K450 @3.0GHZ
OS
64-bit Windows 8.1 Pro
CPU
Core(TM) i5 CPU 4330 Haswell @ 3.20GHz
Motherboard
LENOVO
Memory
12.00 GB
Graphics Card(s)
Intel(R) HD Graphics
Sound Card
Intel HD integtrated
Monitor(s) Displays
HP 25' ISP Monitor
Screen Resolution
1900/1020
Hard Drives
(1) ST1000DM003-1CH162 (2) Generic STORAGE DEVICE USB Device (3) Generic STORAGE DEVICE USB Device
Ok.. Progress.... download the drivers -=> here and save the file to your desktop.. Make sure that you read Brinks tutorial.... You will have to install the driver package in Windows XP copatibility mode. Let us know how it comes out...
My Computer
At a glance
64-bit Windows 8.1 ProCore(TM) i5 CPU 4330 Haswell @ 3.20GHz12.00 GBIntel(R) HD Graphics
Computer type
PC/Desktop
Computer Manufacturer/Model Number
LENOVO K450 @3.0GHZ
OS
64-bit Windows 8.1 Pro
CPU
Core(TM) i5 CPU 4330 Haswell @ 3.20GHz
Motherboard
LENOVO
Memory
12.00 GB
Graphics Card(s)
Intel(R) HD Graphics
Sound Card
Intel HD integtrated
Monitor(s) Displays
HP 25' ISP Monitor
Screen Resolution
1900/1020
Hard Drives
(1) ST1000DM003-1CH162 (2) Generic STORAGE DEVICE USB Device (3) Generic STORAGE DEVICE USB Device