One thing to make sure: Did you run the installer as administrator?
I am signed into the computer as the Admin account during the install.
Deleting pref. file failed to fix importing issue. I can set up a empty folder and direct Lightroom 4 to watch it. In the auto-import menu. The only way to import is by the auto-importing feature. Where a empty folder is to be watched, where images can be dragged into the empty folder and imported that way Another is by a memory card being inserted into computer's built-in card reader. All additional hard-drives, usb connections or import menus fail and the program is forced to close. I think, the problem is linked to camera raw itself. Where photoshop CS5.1 calls for Camera raw 6.6 or earlier and the Lightroom 4.0 calls for Camera raw 7.0 or higher. Until the new release of photoshop CS6 hits the market and computer is updated to that new release, I doubt that Lightroom 4.0 will fix this importing failure! Looks like Bridge is the only program to use until that time! I am seeing a lot of people with the same importing issue and no one has come up with a fix or work-around. Looks like it is best not to install lightroom 4 at all and wait for photoshop CS6 to be released. Then just use Bridge, because lightroom 4 that doesn't import is useless!
LR does not call CameraRaw. For LR CameraRaw hast not to be installed because the CameraRaw engine is built into LR. Otherwise LR would only work if Photoshop and CR are installed on a computer as well, which is not the case.
Another idea: Owner/access rights of the LR folder, the folder where the catalog is located as well as the image folders. Verify that you are the owner or do have full access rights at least.
I am working on W7 64bit as well, without issues, and without PS or CameraRaw installed - just plain LR.
Camera raw is built into Lightroom. It is the engine that makes the corrections within an image. You might not see as a seperate program, like earlier versions of Lightroom. Or having to launch it in a new window to work in camera raw. In version 4 of Lightroom it was made seamless and built into Lightroom.
Lightroom 4 was installed in the admin log-in window. I have all useage rights to any file lightroom creates or adjusts. I am thinking that the Photoshop CS6 beta created some working problem within Lightroom 4. Now that the beta-test program is over, I think the problem is a result of removing Photoshop's last build, before the public beta was released. I do hope, Adobe is working on a solution for people experiencing importing problems with Lightroom 4. I am just grabbing at straws here, trying to find something that will work. I think the problem will go away once computer has the new camera raw build 7.0 that ships in Photoshop CS6. With so many versions of camera raw installed on the computer, I think Lightroom is having issues as a result. Let's hope a patch is in the works, Lightroom 4 is useless if importing files doesn't work correctly.
B&H photo is taking pre-orders for the creative suites, right now. The only way to get support is by purchasing a subscription. Otherwise it is a $35.00 per issue fee. So, I am not sure of what upgrade path I will take. Not loving the cloud at all, with this year of Hackers, I seriously doubt that any cloud will prove to be safe to use. Why would, I want to post my hard work to a cloud where anyone can steal it? But that is a different topic.
For right now the only way to import is by creating an empty folder on the same hard-drive that Lightroom resides on. Setting up auto-import in Lightroom Pref. file to check that empty folder. Folder has to be empty to set up. Then dragging image files into that empty folder. I discovered that Lightroom 4 will not open or look in sub-folders for images. Which means you lose keeping a day's worth of shooting seperate from other folders. Where Lightroom version 3.6 you could.There was a second auto-import that worked, with my built-in memory-card reader. Where in the Lightroom pref.file you can tell Lightroom to auto-import, when a memory-card is detected. ( this is the least viable option, because more memory card become damaged removing and reinstalling them). These were the only two methods, I could get images into Lightroom 4 and prevent Lightroom from crashing. Might have to go back to using Nikon NX to import my images and using Bridge to catalog them.
Lightroom has no connection to ACR used by Photoshop and never has!
Your problem is with your system somewhere and nothing to do with Lightroom interacting with PS.