Hi Laura10,
- Did you remember making any changes to the computer before this issue started?
- Have you tried to boot the computer in safe mode to check if you can boot to the desktop?
- Did you try to boot from the Windows Vista installation disc and try to run startup repair?
- Do you receive any error message?
Method 1
If you have any external device connected to the computer you may try to disconnect the external device except for the keyboard and mouse and try to boot the desktop and check if you can boot.
Method 2
You may access your computer in safe mode and check if you can boot to the desktop.
To boot to the desktop in safe mode keep tapping F8 key during restart. Once you see the option to boot in safe mode select it and press enter.
Access the link to know more about how to boot the computer in safe mode:
http://windows.microsoft.com/en-US/windows-vista/Start-your-computer-in-safe-mode
If it works fine in safe mode, you may put the computer in clean boot state and check if any third party applications are causing this issue.
Access the link below and follow the steps to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7.
http://support.microsoft.com/kb/929135
If your issue is resolved after performing Clean Boot, then follow the steps mentioned in the above KB article to narrow down the exact source.
Also in the same article, see the section on how return your computer to a Normal startup mode by following the steps under “Reset the computer to start as usual”.
Method 3
If you are unable to boot to the desktop in safe mode, you may Disable automatic restart on system failure and make a note of the error message and post it back.
The Advanced Boot Options screen lets you start Windows in advanced troubleshooting modes. You can access the menu by turning on your computer and pressing the F8 key before Windows starts.
This prevents Windows from automatically restarting if an error causes Windows to fail. Choose this option only if Windows is stuck in a loop where Windows fails, attempts to restart, and fails again repeatedly.
Once you’ve disabled automatic restart, you would be able to view the exact error message. Make a note of it and let us know the exact error message.
Access the link below to know more about Advance boot option in Windows.
http://windows.microsoft.com/en-US/windows-vista/Advanced-startup-options-including-safe-mode
Method 4
If you are unable to boot to the desktop in safe mode, you may try to perform a system restore from Windows Reacover Enviornment (WINRE Mode) to an earlier date and check if it helps you fix the issue.
If you have Windows Vista disk you may try to perform a system restore using Windows Vista disk:
a. Insert the installation disc.
b. Restart your computer.
c. If prompted, press any key to start Windows from the installation disc.
Note: If your computer is not configured to start from a CD or DVD, check the information that came with your computer. You may need to change your computer's BIOS settings. For more information, see BIOS: frequently asked questions.
d. Choose your language settings, and then click Next.
e. Click Repair your computer.
f. Select the operating system you want to repair, and then click Next.
g. On the System Recovery Options menu, click System restore and select the date when the computer was working fine.
If System Recovery Options is a preinstalled recovery option on your computer:
a. Remove all floppy disks, CDs, and DVDs from your computer, and then restart your computer.
Click the Start button, click the arrow next to the Lock button, and then click Restart.
b. Do one of the following:
• If your computer has a single operating system installed, press and hold the F8 key as your computer restarts. You need to press F8 before the Windows logo appears. If the Windows logo appears, you will need to try again by waiting until the Windows logon prompt appears, and then shutting down and restarting your computer.
• If your computer has more than one operating system, use the arrow keys to highlight the operating system you want to repair, and then press and hold F8.
c. On the Advanced Boot Options screen, use the arrow keys to highlight Repair your computer, and then press ENTER. (If Repair your computer is not listed as an option, then your computer does not include System Recovery Option as a preinstalled recovery option.)
d. Select a keyboard layout, and then click next.
e. Select a user name and enter the password, and then click OK.
f. On the System Recovery Options menu, click system restore and restore the computer to the date it was working fine.
After running the system restore check if you can boot to the desktop normally.
Access the link below to find more information about system restore.
http://windows.microsoft.com/en-us/windows-vista/What-is-System-Restore
Hope this helps. Let us know the result.
Thanks and Regards,
Srinivas R
Microsoft Support.
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