Flash button is red and camera reads memory card requires format.

Denise - you didn't provide *any* details so the help I can provide may be rather limited, but here goes:

You can transfer pictures to a computer a couple of different ways. The first method requires that you install any software that came with the camera on your computer and reboot. Next, connect the camera (powered off) to the computer with the included cable - which is almost always a USB type on one end and one that fits into your camera on the other. The camera will need to have working batteries, so be sure that they're good. Turn the camera on and the camera software should automatically detect the camera and start up. You should be able to transfer, possibly edit and save your pictures on the computer. If you didn't receive software with your computer, skip the software installation step above - but do the rest. Double-click the Computer icon (to show you the hard drive and DVD/CD icons) and look for a new drive. The new drive represents the camera memory. You can open the drive and work with the picture files just like they were files on a hard drive. Move, edit, copy, delete or save them as you see fit. The drawback to this method is that transfers from you camera are often slow and of course you need batteries. A second method is not limited by these - but does cost money. Keep reading.

The second method requires the use of a "card reader"

An external USB multi-format card reader.

Card readers are powered by and transfer files via the computer's USB port. They run at significantly faster speed than the camera and can be purchased for as little as $10. To use them, install software included with the reader (if any) and reboot. Connect the reader to the computer's USB port. Remove the memory card from the camera and insert it into the appropriate slot in the card reader. A message stating that a new device has been found and software is being installed will appear on the monitor. Double click the computer icon and look for a new drive icon. Double click the new drive to show the image icons on the memory card. Move, edit, copy, delete or save them as you see fit. When done click the "Safely Remove USB" icon in the System Tray and then click Remove. If you don't see this - simply remove the reader from the USB port or the memory card from the reader slot and you will be shown how to do it properly the next time.

Be sure to FORMAT the memory card after you insert it into the camera before shooting new pictures. Formatting the card on your computer is not the same - and should be done in the camera. Formatting removes ALL data from the memory card, so if you wish to leave images on the card to show others on the camera - do not format. As mentioned above, the format should be done before taking new pictures.

Many laptops have an SD card reader. If you do have one, you will need an SD adapter to plug the card in and then to put it in the laptop's card reader. If you do not have one on your laptop you will need to buy an SD card reader and an SD adapter.

Alternatively, you can try putting the microSD card into your phone or digital camera (if it does support one) and connect your phone/camera to the computer to access the data on the card.

The best way to download pictures to a computer is through an optional card reader then there is no problem with the computer not recognizing the camera or downloading the pictures. Using a card reader you would remove the Compact Flash card from your 10D and insert it into the card reader the computer would then recognize it as an external drive. Do not format the memory card in the computer always format in the camera. If you must use the camera as the reader make sure you have plenty of battery power in the camera to do the transfer then turn it off. Have the computer on and connect the USB cable to the computer and the mini USB to the camera. Turn on the camera and the computer depending on you operating system will ether place the camera memory card as a drive on the desk top or you may have to go into your system preferences. Most newer systems the HD icon will appear on the desk top. Which ever system you use make sure you click on the icon when you are finished downloading the images and "eject" the memory card, failing to do this will cause problems with lost files or corrupt the memory card. Happy Holidays from Canada

Use a computer with memory card reader, and read the card using a computer.

If the computer says the same and does not read the card, then the pictures inside the card are usually lost.

If computer instead does read the card, then transfer all picture on computer using the memory card reader, and format the card using complete formatting.

If you need to use the camera tonight, then buy a spare memory card.
If the camera returns same error on different card, then you may have a faulty memory card slot, but that is quite uncommon.

Regards

I suggest you to remove the card from the camera and use a memory card reader to transfer the pictures to the computer. Note that the memory card should be formatted in the camera. Once the pictures are transferred you can reinsert the memory card to the camera and then format it in the camera.

If this memory card will be connected to a camera you can simply put the memory card to the camera and there you can format it using the camera's menu, you can also format this memory card using a card reader that will be connected to your computer, just put the memory to a card reader then connect it to the computer that way you can also format the memory card....

It is possible that the memory card was damaged. This would be by coincidence. Just in case only the formatting is damaged you can try to format the memory card.

As far as reading the card is concerned, if the Mac has issues to read a PC format then it will not be able to read the card from your camera.

Jerry G.

do one thing. as per canons manual:
if any error is displayed when using your memory card do a low level formating of memory card.
but what to do for pictures in it? get a memory card reader from market. its very cheap. its also advisable to use memory card reader to transfer your photos rather than using direct connectiin to computer.
after doing a low level formating then transfer photos inside memory card from system, put it in ur camera, then enjoy.
hope you are clear with your problem. please give a feedback.

many users have the same doubt. as per canons manual:
if any error is displayed when using your memory card do a low level formating of memory card.
but what to do for pictures in it? get a memory card reader from market. its very cheap. its also advisable to use memory card reader to transfer your photos rather than using direct connectiin to computer. bcz any lekage current from computer may damage the camera in some way.
after doing a low level formating then transfer photos inside memory card from system, put it in ur camera, then enjoy.
hope you are clear with your problem. please give a feedback.

can you view the pictures via your camera?  Sounds like the card is corrupt. If the camera can't see the pictures either, you're out of luck.  Or you can try a card reader. Card readers cost about $20 and are easy to find.