OSX Yosemite installation problems :-(

Question

Have downloaded OSX Yosemite and have tried to install at least 10 times and continue to get the message "An error occurred when preparing to install. Try running the application again"  What do I need to do to complete this install?  Tried to find a more applicable community but could not post there :-(

Answer 1

1. If possible, set the system clock as instructed here. If you can only start up in Recovery mode, see below.
Select Get Help Online. Safari will launch. While in Recovery, you'll have no access to your bookmarks, but you won't need them. Load this web page.
Triple-click anywhere in the line below to select it:
date 0801000014
Copy the selected text to the Clipboard by pressing the key combination command-C.
Quit Safari. You'll be returned to the OS X Utilities screen.
Select
          Utilities ▹ Terminal
from the menu bar. A Terminal window will open. Paste into the window by pressing the key combination command-V.
Wait for a new line ending in a dollar sign ($) to appear below what you entered. If it doesn't appear, press return.
Quit Terminal to return to the main screen. Try the installation again.
2. If the date is correct, or if you still can't install after correcting it, see beow.
Start up in Recovery mode, launch Disk Utility, select the startup volume ("Macintosh HD," unless you gave it a different name), and run Repair Disk (not Repair Permissions.) If any problems are found, repeat. Then restart as usual.
If you don't already have a current backup, you must back up your data before you take the above step. You may be able to back up, even if the system isn't fully functional. Ask if you need guidance.
Directory corruption in a MacOS journaled volume is always the result of a drive malfunction. It's not caused by power failures, system crashes, or anything else. You might choose to tolerate such a malfunction once in the life of a drive. If it's repeated, the drive must be replaced, or there is some other hardware fault that needs to be corrected. Ignoring repeated directory errors will result in data loss.