Are you expecting a popup informing you that "new hardware has been detected" or a popup asking what you want to do with the contents of the card?
If the former, that won't happen with the kind of reader used on a 435T/9000. Each of the slots are permanently assigned a drive letter.
If the latter, that means that AutoPlay has been disabled. You can turn it on and/or modify its behaviour in Control Panel.
Personally, I hate pop-ups so I turned AutoPlay off.
This is a known issue. I spent over an hour on the phone with Dell yesterday about this, I'm having the same problem. My card reader worked fine for the first two weeks I owned the computer (Dell studio xps 435t/9000 Windows 7 64 Bit), I would put in a SD card and it would download my photos for me, showed up in explorer, etc. Then I plugged in a Western Digital external hard drive into one of the front USB slots one day and it didn't seem to like that. The drive worked fine, but after that I started getting a message every time I would restart or the computer would wake up with a USB error, saying it couldn't find the USB device. Coincident with that the media reader disappeared and stopped working. Windows couldn't find a driver for the device, I disabled it, enabled it, uninstalled it, etc., etc. nothing worked. The Dell guy was trying to find a chipset to install to fix the problem, but that didn't work either. I have been unable to find the specific driver for the device, as was the Dell guy. Final solution was to reinstall Windows 7, which I just did and the message still came back! I think it kept some of my old files when I reinstalled, so this time I'm going to format the hard drive and do a totally fresh install, but even if that works I have no confidence that the error won't randomly reappear in a few weeks as I have read a number of people online are having this exact same problem with the media card reader on this system. The Dell guy said that if the fresh OS install doesn't fix it they'll send me a new reader, but I'm sure that's not the problem, it's clearly some sort of software compatibility issue as far as I'm concerned. I'll post again if I have any success.
I have the same problem and same experience. I worked with Dell on the phone twice for about 4 hours total with nothing to show for it. They tried every driver they could find but no help. A Dell technician came by today with a new reader but the same problem. The USB works but no cards are read and it shows as an "unknown device". My theory is that it worked prior to Windows 7 but has not worked since updating Vista to Windows 7(6 bit). In any event, there appears to be no help and Dell seems unable to decide what driver to use.
This is weird. I also have a new XPS9000 with Win7 64bit factory installed. When I first checked in My Computer when I got the machine, the card reader drives showed up. I installed a portable WD USB drive, but connected it through one of the rear USB ports. This drive shows up as Drive F:. Now, the card reader drives do not show up in My Computer, BUT, when I put an SD card in the slot, it reads fine and the drive then shows up in My Computer as Drive G:. This tells me that the card reader drives are not assigned permanent drive letters, but still doesn't fix the problem some of you are having. Question? If you insert a card in the card reader, does Win7 flash up the bubble on the taskbar that there is a disk drive with the letter corresponding to the card slot in use?? It does on my system. Also, under USB devices in Device Manager, it shows a Realtek USB Card Reader 2.0 device, and reports it is working correctly. For what it's worth, there is a newer driver on the Realtek site than the one I have on my system. Mine is 6.1.7100.30093, dated 6/4/2009 and the one on the Realtek site is 6.1.7600.30109, dated 11/25/2009. I'm not going to mess with mine as it's working but it might be worth a try to update the driver from Realtek.
AnClar, On your system do you have the "Show All Folders" box in the Navigation Pane section of the General tab in Folder Options ticked - on my XPS420 I've found I have to have this ticked in order to see the Media Card Reader (I know its a different piece of hardware from a different vendor) drives in Explorer. I can make them come and go by ticking and unticking this box.
XPS 420, 8GB, Windows 7 Home Premium SP1 64 bit
Arrrgh! Never mind...now I'm in the same boat as everyone else. The reader shows as an unknown device, and if I manually try to update the driver, it shows the Realtek 5150 Card Reader, but with error 10 "This device cannot start". This is after a full system restore off the Dell recovery partition. Maye the h/w is just defective. Off to tech support hell. I'll update if anything changes.
I just got off the phone with Dell tech support. They wanted me to check the cable connections to the card reader. Unfortunately, it's tucked in above the HDD bay and I can't reach the cables to see if they are seated OK. Now it gets odder.....when I reassembled my computer and restarted it, the driver for the card reader installed OK. The ONLY thing I may have done differently is to connect the keyboard and mouse to different USB ports than I had them in before. Now I'm back to where I was originally. That is, I have no marked bad drivers or devices in device manager. The only drives that show up in Device Manager and My Computer are the HDD array and the two DVD drives. However, when I put an SD card in the reader, it reads normally, and the drive does show up, both in device manager and My Computer. I can use it normally. When I eject the card, the drive disappears from both device manager and My Computer. Personally, I'm happy with that...I mean the reader works. Dell, however, wants to put a new card reader in the machine. Fine by me, but I don't think it'll change a thing. My guess is that either this is normal behavior for this setup, or else there is some really subtle, flaky problem in the USB h/w/driver setup. In any event, I'll update again after they change the card reader out. I'm going to stand over the tech's shoulder to make certain he puts eveything back together correctly, though and doesn't screw anything else up in the process.
I very much doubt you have a hardware problem with the Card Reader - a lot of people have had various card readers replaced by Dell to no effect. I have a spare one sitting beside me which they didn't want back as I type this - replacing the card reader may or may not change anything, but it will not resolve the problem permanently. Earlier I asked if you had checked some settings in Explorer but I notice you didn't post a reply - I think its worth your while just checking my earlier suggestion and at least letting us know whether you have these boxes ticked in the Navigation Pane section.
XPS 420, 8GB, Windows 7 Home Premium SP1 64 bit