I just upgraded (fresh install) to win 7 64-bit and my hauppauge PVR500 MCE no longer works right (with Media Center) because I have 4GB RAM. see http://www.hauppauge.com/site/support/support_pvr150.html Is there a way to reduce the amount of RAM Windows 7 sees at boot up by a few MBs to (hopefully) work around the problem? Alternatively can I create a ramdisk or something at boot up to "steal" some RAM before Windows see it?

Type msconfig into the start search box. Press enter Select the boot tab. Select Advanced options. Put a check in the maximum memory box and enter 4095MB Reboot

thanks for the reply. the system now reports "4.0GB installed (2.0 GB unusable)". I confirmed in taskmgr that system only has 2048MB available. in a related update Hauppage replied to me that the problem is the "result of severe limitations in the Microsoft DMA architecture for 32 bit bus subsystems in a 64 bit OS environment. This limitation results in buffer starvation at the driver level and thus the frame rate drops to very low levels." if this is true, will reducing the available RAM fix the problem or would I have to go to 32-bit windows 7? is there another fix for this DMA "limitation"??

I'm not sure what they are saying but I used that same card with 4GB of RAM by doing what I posted above. I do not know why your system is only reporting 2048MB useable.

That seem your machine cannot recognize full RAM. Try to update all driver for your machine, and make sure the drivers are support to Windows 7. Also update BIOS to the latest version. If the device incompatible with Windows 7, it will cause unexpected issue. In addition, you can go to BIOS to check how much RAM could motherboard recognized. Regards, Leo Huang Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi, Did your issue solved? Please feel free to give me any update. Thanks. Regards, Leo Huang TechNet Subscriber Support in forum. If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi, As this thread has been quiet for a while, we assume that the issue has been resolved. At this time, we will mark it as ‘Answered’ as the previous steps should be helpful for many similar scenarios. If the issue still persists, please feel free to reply this post directly so we will be notified to follow it up. You can also choose to unmark the answer as you wish. BTW, we’d love to hear your feedback about the solution. By sharing your experience you can help other community members facing similar problems. Thanks for your understanding and efforts. Regards, Leo Huang TechNet Subscriber Support in forum. If you have any feedback on our support, please contact tngfb@microsoft.comPlease remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

I went into my BIOS and turned off "memory mapping" so now my MB only offers up 2.7GB of RAM to windows and the card works. Short of getting the latest BIOS (which is 3 yrs old now anyway) I do have an up to date fresh install of Win 7 64-bit (only about 2 weeks old.) It seems to be a device driver problem that isn't being updated by Hauppauge and they're trying to tell me it's Microsoft's fault. Am not buying it nor am I buying the latest card they want me to buy from them to fix the problem. I'll live with 2.7GB of RAM for now and figure something out when I really need the extra RAM I bought. If there are other ideas out there I'd like to hear them.

Try reducing the RAM size to 4094MB. Type msconfig into the start search box. Press enter Select the boot tab. Select Advanced options. Put a check in the maximum memory box and enter 4094MB Reboot

I tried that again (turning memory mapping back on in my BIOS first) with 4094MB this time instead of 4095MB (per your previous post) and it still ends up with 4GB seen by windows but only 2GB usable. My current setup (BIOS memory mapping off) gives me 2.7GB so I went back to that. Is there no low level RAMdisk device I can load prior to Windows to reduce the RAM it sees while making productive use of the otherwise unused RAM?

I am unaware of any. I have set this memory limit on many machines for this TV card and have never had the reduction that you are seeing. I might suggest trying some even lower limits, there may be something in your hardware that get remapped.

When booting up, press F8 or similar key to enter advanced bootup options. press <tab> to go to the Windows Memory Diagnostic.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

When booting up, press F8 or similar key to enter advanced bootup options. press <tab> to go to the Windows Memory Diagnostic. to do or to look for what? I presume you mean with the BIOS memory mapping on (i.e. 4GB enabled). do I do it with msconfig maximum memory set to 4094MB or without it? thanks.