Poor performance after upgrade to Windows 7 Professional

[Zatnikitelman]

Last week, I finally decided to make the upgrade to Windows 7. Because I'm a student, I was able to get a significant discount, but only the professional version. My desktop had Vista Home Premium before so I had to do a clean install (which I would have done anyways). So I've updated to Windows 7 professional, and begun reinstalling stuff not needed for school since I'm on break (read: games). However, anything that's graphically intensive refuses to run smoothly, namely FSX, Orbiter, and Wings3d.
I've used Orbiter as a benchmark as I'm most familiar with it as are most of the people here. With the built-in client, I get 30+ FPS. With the D3D9 RC35 client, I got over 100 on Vista, but now I get a maximum of 12. This is in fullscreen at several different Hz, but all at 1920X1080 and with vertical sync enabled and disabled.
With Flight Simulator X, I'm using virtually the same settings I did on Vista, but am only seeing fps down below 5fps and it's not smooth at all.
With Wings3d I'm seeing a sluggishness that I wasn't seeing before, but there's no real graphical settings to adjust to remove detail or anything like there is with Orbiter and FSX.
The system is up to date as far as Windows update is concerned, and I have the latest driver for my video card.
Here's my detailed computer specs:

HP Pavilion p6140f
Name Intel(R) Core(TM)2 Quad CPU Q8200 @ 2.33GHz
Physical Memory 8192 MB Total
Video Processor GeForce 9800 GT
   Memory 512 MBytes
   Dedicated Video Memory 487 MB
   Driver Version 8.17.12.8562
   Driver Date 2011-10-15 00:00:00

I know my computer is a bit old, but I'm not necessarily looking to max out the graphics settings on every game, just play with the same smoothness I did under Vista, the presumably inferior operating system.
Does anyone know what I can do to get back where I was with Vista?
Thanks for any help,
Zatman-Matt

[EDIT]Aero was, is, and will forever be disabled

 

[TerraMimic]

Somebody correct me if I'm wrong, but I've seen several comments to the effect of the Cleartype settings are what's causing the problem. Something about how it runs intensive AA on text because they think that slightly jagged letters are apparently suddenly a problem.

 

[dbeachy1]

In the video tab, make sure that "Always Enumerate Devices" is checked and the 3D Device is set to "Direct3D T&L HAL". Also make sure you installed the latest video driver for your video card -- Windows 7 performace should be comparable to Vista.

 

[Hielor]

Last week, I finally decided to make the upgrade to Windows 7. Because I'm a student, I was able to get a significant discount, but only the professional version. My desktop had Vista Home Premium before so I had to do a clean install (which I would have done anyways). So I've updated to Windows 7 professional, and begun reinstalling stuff not needed for school since I'm on break (read: games). However, anything that's graphically intensive refuses to run smoothly, namely FSX, Orbiter, and Wings3d.
I've used Orbiter as a benchmark as I'm most familiar with it as are most of the people here. With the built-in client, I get 30+ FPS. With the D3D9 RC35 client, I got over 100 on Vista, but now I get a maximum of 12. This is in fullscreen at several different Hz, but all at 1920X1080 and with vertical sync enabled and disabled.
With Flight Simulator X, I'm using virtually the same settings I did on Vista, but am only seeing fps down below 5fps and it's not smooth at all.
With Wings3d I'm seeing a sluggishness that I wasn't seeing before, but there's no real graphical settings to adjust to remove detail or anything like there is with Orbiter and FSX.
The system is up to date as far as Windows update is concerned, and I have the latest driver for my video card.
Here's my detailed computer specs:

HP Pavilion p6140f
Name Intel(R) Core(TM)2 Quad CPU Q8200 @ 2.33GHz
Physical Memory 8192 MB Total
Video Processor GeForce 9800 GT
   Memory 512 MBytes
   Dedicated Video Memory 487 MB
   Driver Version 8.17.12.8562
   Driver Date 2011-10-15 00:00:00

I know my computer is a bit old, but I'm not necessarily looking to max out the graphics settings on every game, just play with the same smoothness I did under Vista, the presumably inferior operating system.
Does anyone know what I can do to get back where I was with Vista?
Thanks for any help,
Zatman-Matt

[EDIT]Aero was, is, and will forever be disabled

Maybe try moving to a previous graphics driver? Sometimes "latest driver" is not always the best idea. Uninstall the driver and then grab the one from windows update, maybe.

Also possibly try a benchmarking program to see if you can isolate the problem to GPU or CPU...

 

[Zatnikitelman]

Uninstalling and letting Windows find its own drive has worked for now. It shows as version 185.93. Tomorrow I'm going to start with the oldest update on nVidia (260) and see what happens. Windows Update has also found a driver for the card released in May, 2011, and I may try that one first.
What benchmarking program do you recommend? I found something called Performance Test, but can't see how its results would help the current problem.
Thanks

 

[Hielor]

Uninstalling and letting Windows find its own drive has worked for now. It shows as version 185.93. Tomorrow I'm going to start with the oldest update on nVidia (260) and see what happens. Windows Update has also found a driver for the card released in May, 2011, and I may try that one first.
What benchmarking program do you recommend? I found something called Performance Test, but can't see how its results would help the current problem.
Thanks

Yeah, when it comes to graphics drivers, "latest" is not always "best"--in general, stick with a driver that works and only upgrade if there's a reason to do so.

I'm reminded of that one NVIDIA driver update that would cause fans on some cards to stop working, resulting in the card frying itself...

 

[Arrowstar]

I'm sure that was merely a "sale-enhancing feature" on the part of nVidia.

Zatnikitelman, if you are still having trouble, I'd be happy to let you know which driver version I'm running here...