Vista - Vista Start Up Issue

Hi All,
For the last two days Vista is giving startup issue in my Notebook. First of all it is taking so much of time to go to the log on screen. Once I give the credentials it is showing a dark screen showing that Access denied to desktop and at the status bar giving a popup with the message "Failed to connect to windows services" and in a couple of secons it will restarts. The same is going on even when I use safe mode for start up.
I thinks some of the OS files has been corruptd or deleted. And I didn't have recovery disk created.

Kindly help me in fixing this issue.

Thanks in Advance!

OK firstly have a look Here this tutorial will solve most solvable issues.

Seems it has failed to access the data in the HD caused by either corrupted OS or faulty connection to your HD. So, I would probably try to boot with CD/DVD first and then check the connection by remove and reconnect the HD to see if it help.

Posting you computer specs may be helpful in this inquiry. Good luck.