How do I format an SD card for a Vivicam 3785?

Card is too big. Specs in the manual say

SD memory card (optional) (up to 512MB capacity)

https://www.manualslib.com/manual/336674/Vivitar-Vivicam-3785.html?page=54#manual

..

This should do it - this comes from the manual Formatting will do what you want.

Formatting an SD Memory Card or Internal Memory This utility formats the internal memory (or memory card) and erases all stored images and data. 1. Press the button to turn on your ViviCam 3785. 2. Press the MODE button twice to enter [ ] Playback mode. Then press the button to enter the Playback menu. 3. Select [Delete] by using the / buttons, and press the button. 4. Select [Format ] by using the / buttons, and press the button. 5. If you want to format your SD memory card or the internal memory choose [OK] by pressing / buttons, then press the button to confirm.
To cancel the action, select [Cancel] instead.
[No Image] pops up after the SD memory card or internal memory has been formatted. Note:
Be sure the SD memory card is properly inserted into the camera before formatting it.
To format the internal memory, be sure to remove your SD memory card first.
Formatting will erase all information (even unrelated , non-camera data) from the memory/card.
For complete compatibility, be sure NOT to select FAT 32 as the file system when you format the SD card in your computer. Memory cards formatted in FAT 32 file system will not be recognized by this ViviCam 3785.

Assuming it is not actually full, this might mean the card is incompatible with the camera (too high a capacity) or it might mean it needs formatting. Usually a camera will say if it needs formatting, so I would check the camera specs to see whether you have a memory size it can handle. SDHC cards are not backwards compatible with SD cards.

Well you need a SD card "Secure Digital (SD), and a 2GB is 7.54 at Walmart they don't sell 1GB cards but you could find one on ebay.

Manual says that camera only supports up to 512MB. Just tried it with a 2GB card now--gives a "Card Full" error.

Any SD card will work in this camera. The largest capacity card is 2 GB. There are cards that look identical to SD cards that have much larger capacities, but these are SDHC (Secure Digital High Capacity) type cards - not SD cards; an will not work in your camera.

You can download your camera manual here:

http://www.retrevo.com/support/Vivitar-3785-Digital-Cameras-manual/id/200ag818/t/2/

most likely the memory you are using is either corrupted or not damaged, try using a diferent one similar to the SD card you are using...
cheers

I checked out the user manual and it looks like the SD memory card slot is located right next to the battery. Just open the battery compartment and look near the hinge and you will see a place to put an SD memory card. Here is a link to a pdf version of the manual which is nice to have even if you have the printed version:
Click HERE.

Take Care,
-WN

Might be that the card is too large/small for camera to recognize, or it is a newer type of memory. Look up the specs for camera and compare to stats of memory card.

Try the manufactureres web site.
However if you computer is a Windoes machine[ME/2000/XP/Vista
No disc or sofrware is required.
Windows can do it all