Windows 7 - Installed USB3 driver on Win7 - monitor goes blank

I installed a Sabrent 2-port PCIX-USB3 "black" card into my HP P6228 desktop PC running Windows 7 Home Premium 64bit. I installed a driver from their web site, and everything continued to work OK, except the USB3 appeared to run only a bit faster than USB2. I opened a problem case with Sabrent and they replied that I should install their latest driver and firmware from
ASMediaUpdate.zip
I downloaded the zip file and extracted the files as directed. I then powered down the PC and unplugged all USB devices except the mouse. I rebooted and shut down the misc. stuff like HP Assistant, stopped the Avast AV, and then ran the USB driver "setup" file from the extracted driver folder as directed. Driver installer appeared to run perfectly and Device Manager displayed my USB as c:\windows\system32\DRIVERS\asmtxhci.sys V1.14.4 11/22/2011 PCI Bus 4, Device 0, function 0. I also viewed the driver install log which looked good. So, I rebooted normally to get ready to install the firmware upgrade that came included in the downloaded zip. I rebooted and shut down the misc. stuff like HP Assistant, stopped the Avast AV, and right after that the monitor screen went blank and stayed that way. I had to power down the PC with the power switch. I rebooted again and started a browser and clicked up a couple of web pages - OK. I then started another browser to go to my Hotmail - and right after that my monitor screen went blank again and the PC will again have to be powered down with the power switch. So now my perfectly running PC is broken and I need you help in knowing what to do. Please help. Charlie

Are you sure the drivers were for a 64 bit OS, did the card itself come with 64 bit drivers.

I don't specifically know how to verify that the installed driver is 64bit - can you download the zip and tell me?
In the problem case I opened with Sabrent I did say that I was running 64bit Windows 7. One of the files in the unzipped folders was named amd64 something-or-other, fyi., but that may not mean anything. Also, the readme in the downloaded zip said that 64bit Windows 7 is one of the supported OS's. So, to me it looks like Windows 7 64bit should be OK, but I'm way too much the rookie to say for positive about this stuff. BTW, I never did plug anything back into any USB ports after the driver "upgrade" - but the mouse is still plugged into it's USB2 slot . What to do?

Here's link to the problem case with Sabrent...
http://www.sabrent.com/support/ticket.php?track=NZV3NB9ZHS&Refresh=41662

Tech installed old Sabrent driver from CD that came with the card. Maybe the older driver has issues of some kind, but at least it did not break my PC like their newest (V1.14) driver did.

I think I'll next try the Western Digital PCIx-USB3 card which supposedly uses NEC chips rather than ASMedia chips. Amazon ratings for the WD card are pretty good. But the Amazon price is nearly $38 so I will wait for a sale or a price drop. If you have good or bad experience with the WD card please let us know.
Amazon.com: Western Digital SuperSpeed USB 3.0 PCI Express (PCIe) Card: Computers & Accessories

Seems like I've made additional replies/postings to this thread that are missing.... not sure.

install it in windowsxp sp2 compatibility Mode

I'm awaiting delivery of my WD PCIx-USB3 2-port card.
I'm running a desktop Windows 7 SP1 64bit Home Premium system, fully patched, and I've not read anywhere else that suggested that the driver should be installed in XP SP2 compatibility mode. Why do you say the driver should be installed in XP SP2 compatibility mode?

I installed a WD PCIx-USB3 2-port card with the NEC chip(s).
It functions OK but it still has the problem with the USB2 HD going into autoplay every time the PC awakes from sleep mode. This does not happen when the HD is plugged into USB2 ports that are on the MOBO. I guess there is no fix for that problem.