The panasonic dmc tz3 was given to me with no software or usb cords, i tried to plug it in to my computer using my own usb cord but the camera doesnt respond . how do i upload my pictures to my computer

Instead of using the card to transfer to computer, transfer with a USB cord and open the file it's in. Cut and paste to your computer's folder.

Take any media card out of the camera. Connect the camera tot he computer via camera USB cord. Transfer photos from internal memory that is now accessible because no other media is present. Delete after transfer if you wish.

You don't need any special software.
The best way to download pictures from your camera to your computer involves removing the memory card from the camera and plugging it into a card reader (either built-in to the computer or connected via USB or FireWire). This is likely to be faster than connecting the camera to the computer, and won't run down your camera's batteries.

Once the card is plugged in, it will appear to your computer as a removable drive. You can use the operating system's drag&drop facility to copy pictures from the card to the computer's hard drive, the same way you copy any other files. Or you can use any photo cataloging program, such as Windows Photo Gallery or Picasa.

In the menu system of the camera, scroll until you find "copy" where you are given the option of copying the internal memory to a card in the camera.

Follow the instructions in the "Copy" subsection of the "Using PLAY Menu" section of the manual (page 72 in my copy). If you need a manual, you can download one at
http://service.us.panasonic.com/OPERMANPDF/DMCTZ2.PDF

It seems Panasonic dmc-zs3 seems don't support charging the panasonic battery when pluging in computer by USB, Maybe you can find a USB adapter charger, or using a special charger for it.

If you're just trying to download your pictures, use a card reader. When you plug it into a USB port on your computer, an icon will appear on the screen with a name like "noname" or something similar. Just double-click on it and your pictures open.

I don't know that I can help you fix it, but I can try. Here are my thoughts... Check the battery first. If it's like a normal battery, like AA or AAA batteries, replace them and try turning it on.
If it's a flat lithium battery that you recharge using a power cord that plugs into the camera, you might want to buy a new one. Charge it fully over night and try powering the camera up in the morning.
You never mentioned what the error message was! So I can't help you there.
Next, you might try connecting the camera to your computer and see if it comes up. Also, check with Panasonic and see if there's a way to reset your camera. Maybe there's a way to do a software reset. Also check to see that there isn't a downloadable software upgrade or patch available. Lastly, you may want to consider Panasonic customer support/technical support, they may be able to better help you diagnose the issue with your camera.
I have a Lumix too. I have an DMC LZ10, my daughter has a DMC TZ3. They're similar in many ways, and yet they're different in many too. Mine uses AA batteries, hers uses a flat lithium rechargeable that uses a power cord. The internal software is pretty much the same (sort of). Enough so that I can work the settings on hers without having to reference the manual.
As a computer tech, my first impressions are that you're having either power issues, or software issues. Eliminate the variables. Start with power and work your way out from there. If it behaves the same with any battery, you've eliminated the power issue. Now it's software. Simple enough?

Use a card reader to download your pictures to a folder you create on your desktop.

try using a different computer or a different card into the camera.