Programs (like App Store) missing from computer

Question

Model Name:          iMac
  Model Identifier:          iMac4,2
  Processor Name:          Intel Core Duo
  Processor Speed:          1.83 GHz
  Number Of Processors:          1
  Total Number Of Cores:          2
  L2 Cache:          2 MB
  Memory:          1 GB
  Bus Speed:          667 MHz
  Boot ROM Version:          IM42.0071.B03
Many programs are missing from the computer, when new user account was created the icons were question marks and failed to do anything when clicked.
There are now 5 lines going vertical across the screen, the iSight has stopped working. Many different forums have linked the lines and broken iSight toghether as a massive hardware failier due to production errors. I can't figure out why all of these apps are missing and why Software Update refuses to update them and fix the problem. i would do a factory restore if the disk wasn't lost.

Answer 1

Do you mean your original install disk or the Snow Leopard disk is missing?
If it's the original install disk, you can call Apple, give them your serial number, and they should be able to send you replacement disks for a nominal charge. If it's the Snow Leopard disk, you could easily buy one for $29 or less retail.
Software Update will only update apps that are already on your Mac - if they are missing, they can't be updated. I'd normally suggest that you download the 10.6.7 combo updater from the Apple download site; however, since you are having multiple problems, updating a messed up system is not a good idea. So, it would be best to get either of the disks, back up your hard drive or, at least, your important files, and then verify/repair the hard drive and reinstall.