Bought new SD card for my Gateway DC-T50 but when i turn it on give me card error

on the side of the card there is a little black peg stickin out slide it to unlock then format it when you dont want anyone to erase whats on it you lock it, then snap it off in the meantime slide the little black lock on the side of the sd card to unlock try thst

Refer to the manual page below - note the last 2 items
If you take the camera and the card to a sales outlet the assistants are usually helpful

Inserting an SD Memory Card(Optional)
All images and video clips taken by the camera can be stored in an SD (Secure
Digital) Memory Card. Even if the camera's power is OFF, the images saved in the
SD Memory Card are not erased. An SD Memory Card can be repeatedly read and
written. You may also expand the memory capacity up to 512MB so that you can
store additional images and video clips.
1. Make sure the camera is off.
2. Slide the battery/SD Memory Card cover in the direction of the [OPEN] arrow.
3. Insert an SD Memory Card :
The front side of the memory card (printed
arrow) should face towards the front side
of the camera.
If the card cannot be inserted, check the
orientation.
4. Close the battery/SD Memory Card cover.
To remove the SD Memory Card, make sure
the camera is off. Open the battery/SD Memory Card card cover. Press
lightly on the edge of the memory card and it will eject.
Note:
If the camera is powered-on without the card, the "NO CARD" message appears on
the LCD monitor.
To prevent valuable data from being accidentally
erased from an SD Memory Card you can slide the
write-protected tab (on the side of the SD Memory
Card) to "LOCK".
To save, edit or erase data on an SD Memory Card,
you must unlock the card.
MultiMedia Card (MMC) can not be used.
You need to format an SD Memory Card before using it in this camera

The camera uses SD cards. I assume your new card is 8GB, not 8MB as you stated. If this is the case, it's an SDHC card. While it fits into the slot, it is electronically incompatible and will not work in the SD-only camera. You need to use SD cards, 2GB and smaller.
You may download a copy of the manual here.

If this question is also about the DC-T50, then you need to replace your SDHC card with an SD card, as I mentioned in another response.

Hi, The DC-T50 only takes regular SD cards up to 512 MB in space. Most cards that are sold now are SDHC, which are NOT compatible. If you can find a 512MB SD card, it should be extremely cheap.
Happy Shooting!

Is it an SDHC card? SD and SDHC cards fit the same slots, but many cameras won't work with the SDHC (high capacity) cards. SDHC is not backwards compatible.

http://www.rekam.ru/drivers/dcj01x.bin
Download the firmware above... Copy it to a freshly formated by the camera SD card..  hold the up arrow for all 3 100%'s  turn the camera on it takes 2 min  

try a 512mb because your camera could be older then the 1 and 2gb memory cards can handle...or depending on where you are..you could take it to Best buy and they could tell you...hope it helped =)

this camera is kinda funny, i have the same one, but it only takes pictures with the cards it likes, i guess, but i say get a new card, but my camera <same one> seems to like sandisk cards. you can get them anywhere, like target, walgreens, wal-mart, anywhere