The usb ports on my acer 5250-0650 do not work when a memory stick is installed.

1. Confirm the USB port on the computer you are connecting your printer to is being recognized by your computer. The easiest way to do this would be to plug a known good USB Memory stick into the USB port you want to use. If you can read the contents of the USB Memory stick then the port should work. Remove the Memory stick, start the printer installation program (Make sure you don't the printer connected), want until the setup program tells you to connect the printer before you attach the Printer's USB cable.
If the printer isn't recognized try a different USB port, when picking a new USB port to try select a higher priority port, for example in increasing priority from, an external USB hub, a powered external hub, a monitor based hub, USB ports on the front of the computer, up to the USB ports at the computer rear. For USB ports on the same circuit select an USB 2.0 before an USB 3.0 port

Do you have a Sony memory Stick?
When you plug in usb drive does your computer recognize it?
If not the try a different usb port, then try on a different computer.
If it still is not recognized throw it away it is damaged.

Has the computer recognized the memory card in the past? If so, try download and reinstalling the memory card driver.

Get online and got to www.google.com In the google search box type: "Acer Support" (without the quotes and put your manufacturer name before Support). Look for downloads and drivers. Enter your model number and operating system when requested. Download and install the Card Reader drivers.

If after installing the drivers the reader still does not work, you can purchase a multi format card reader that will plug into you usb port from Tiger Direct for less than $15. at

http://www.tigerdirect.com

When the site comes up just put in the search at the top "SD Card Reader or XD Card Reader" depending you your type and press GO. You can sort the returned results by Price Low to High.

Do you have a USB Cable that came with the camera that you can plug into one of the usb ports on the computer? If so, try that. It's another way of getting pictures off the camera. Plug the cable on the camera and into the computer then turn the camera on. The computer will recognize the camera and install the drivers. You can navigate through the camera folders just like you do any other device to find the pictures.

1. The TV and drive may not be compatible with each other. 2. The formatting of the drive could be the problem. The USB memory stick would be formatted as FAT32, but the Iomega drive would have been formatted as NTFS. Maybe the TV can only read drives formatted as FAT32 and not NTFS.

Find a USB memory-stick, and find a computer with Internet access and an available USB port.
Put the memory-stick into the USB slot.
Browse to ACER's web-site, and select your specific model of the Aspire line, and select Windows XP, and select network-controllers, and download the device-drivers, and copy them onto the memory-stick,.
Walk the memory-stick to your Acer, and install the device-driver.

when you insert the stick it is assigned a drive letter. In windows explorer make a note of the drive letter. Right click on what you want to copy then send to that drive.

Find a friend with a computer that does have a CD-ROM, and a USB port. Purchase a USB memory-stick that has at least 1GB of memory.
Get your friend to copy all the files from the CD-ROM to the memory-stick, including any "hidden" files.

Then, put the USB memory-stick into your computer, and install the software.

does your usb mem stick have any light indicators? if yes , whenever you put you usb stick, does it light? if it lights are USB ports is still ok,  You just have to reformat or partition you USB stick.
(you can also try other devices like usb mouse or any usb devices that lights up when you connect it)

if there are no lights if you plug, or no indication that a power goes to your stick, its possible that your usb your are busted. if this is the case, if your laptop has a PCMIA slot, you can find a pcmia USB card, if you dont have. your only option is replace the  motherboard.

try using different USB port. if the it is unknown device. means the machine didn't recognized the device. you may have to install the device driver. (windows is a funny thing).

Device manager shows the USB port if they are attached to you notebook. And in your case they are attached. So it will show it. Now in your case the problem is in your USB. Get it changed. If it is in warranty peroid then dont u take any risk. Let it be replaced. Or give your notebook in warranty period to the company from which you bought.