My Vivitar takes blurry pictures. Kindly show me what to do to sharpen the focus. Thanks.

Blurry pictures are not an easy photoshop fix. If the image is out of focus or has a motion blur it will be very tough. It really depends on what you are looking to use the image for as well. Sharpening can help but will be noticable if you try to make a large print.

Is your camera in the macro mode?
There's a slide switch on the end of the camera, near the USB slot. Slide it from the flower to the mountain, then take a picture of something at least three meters (ten feet) away. Is it still blurry?

For taking pictures of things close to the camera, switch to macro mode. There's a slide switch on the end of the camera, near the USB socket. Slide it to the flower position for macro.
Don't forget to switch back for taking "normal" pictures.

There are three main reasons for blurry pictures.
Pictures may come out blurry if they're not focused properly. If some objects are sharp and others are not, this may indicate focusing on the wrong subject. This is usually not a major problem with compact point&shoot cameras since they have such a wide field of focus that almost everything will be in focus anyway. However, make sure the macro/far switch is set to the appropriate position for your picture.
Subject motion. If moving objects blur while stationary objects remain sharp then the shutter speed is too slow to freeze the motion. Try switching to the sports mode, and/or add more light.
Camera motion. This is the most common cause. Set your camera on a table or other stable surface and use the self-timer to take a picture. Take another one while holding the camera. Compare the two on your computer.

1) Check if there is a ring on the lens that you can adjust to sharpen the focus, 2) try the tips in the article How To Improve Your Webcam Video Quality.

Make sure the lens is clean
Some webcams have a focus ring around the lens you can rotate to sharpen the image - like a telescope.
Others rely on software and you set the focal length for the best picture.
You can try the Philips website for support
http://www.support.philips.com/support/sms_page.jsp?userLanguage=en&userCountry=gb

On digital cameras it is always best to press the button half way down before taking the picture. This helps the camera focus, thus preventing blurry images. Always, always press the button half way down. Secondly, if you are still getting blurry pictures, there is a possiblity that the sensor in your camera is bad. I don't know how old your camera is or how long you've had it, but you would need to send it for repair, exchange it, or if it's under warranty maybe they'll send you a new one.

Auto focus not working - Under warranty? One year from date of purchase. If not, take it to your Authorized Service Center. I know of one in Florida, I don't know where you are located

how old is the Camera? If under a year return it via retailer If over a year contact the Technical Support team at Vivitar. It seems like a damage to me however in which case new camera - repairs will not be an economic proposition

For some reason the whole image is just a little out of focus. It's beyond "soft". Maybe there's some film on the lens or maybe you are inducing the slightest amount of camera shake. Whatever it is, it seems to sharpen up well (unlike most camera shake). Notice that even the people in the BG sharpened up nicely. I know zero about this camera. I'd advise you to take some shots of some detailed, contrasty type subjects and see if you get better focus. If not the camera may need repair. Or, maybe both of us are expecting too much, image sharpness-wise, out of this camera.