Suddenly my camera won't start up, there nu big scratch or something at all.

PC with Windows 7, try to download photos (79 on camera) using a usb cable. Get error: UDB not recognized. I did update windows 7 32 bit software displayed on Nikon's site, but still receive the error message and my photos can not be downloaded. My PC does not have a card reader. Can only download with a USB cable.

in low lite areas or dark the flash pops up but does not flash

There is a single red dot that appears in the same location on all my pictures. If a picture is underexposed, it will also cause a red streak down the photo. I have had this problem consistently for years, in all settings, but since it is just one pixel I didn't start noticing until I became more serious with my photography and editing.
Is this something that can be repaired?
You can see an example with the red dot circled here:

I am looking at buying the 70-300 mm f/4.5-5.6G IF-ED lens for an upcoming safari vacation but am not experienced with changing camera lens. Any help would be greatly appreciated. Thanks

it's been hit or miss with taking pictures. sometimes it works, but more often than not, i'm having trouble. won't focus and won't take a picture in auto. if i switch functions (to portrait or landscape and press the shutter a few times, i might get a picture. then i return to auto and do get a picture or two before it quits again. seems to be related to the auto focus ... if that's working, i get a shot. otherwise, nothing. btw, i only shoot in auto, i don't know manual yet). THANKS!!

I have a D40 and recently purchased a telescope I have all the adaptors to attach the camera body to the eyepiece but the camera thinks there is no lens attached does anyone have any suggestions as to how I should set the camera up in this configuration?

The battery cover for our Nikon D40 has gone missing...and we need to replace it but have no idea if we can find that a store or if we need to purchase it directly from Nikon USA?

Thank you for your assistance.

I'd like to use my remote for an extended period of time (long than the maximum auto off of 15 min.)
After the camera auto off's - all the settings switch back to the defaults. I've tried this on auto and program settings with no success. I want the shooting mode setting to stay ON in the quick-response remote. Please, help. (This is for my wedding on 11.11.11)
Also, is their any way to keep this camera on? To avoid the auto shut off.

i got the kit lens 18-55mm, 35mm and 55-200mm. Out of all of my lens, the 35mm lens won't auto focus. I tried with my other lens and they can auto focus just fine :(