When I click shut down my Dell Inspiron 1545 won't shut down. Help!

To update bios on your laptop, you laptop must be booting to windows, you should be able to use it.
Click on the below link, this will direct you to the dell support site.
http://www.dell.com/support/home/us/en/04/product-support/product/inspiron-1545/drivers
Once you click on this link, choose the operating system you are using and scroll down to find the BIOS, click on the drop down and click on download. Save the file to your desktop and once it is downloaded, click twice on it and it will start the installation.
Ensure that the battery is charged more than 10% and the ac adapter is connected.
It is always recommended to updated bios only if you feel there is any issue with it.

its shutting down or get freezing? meant the display get freezed and nothng works?

Try right clicking on the speaker icon in the right lower corner. This should open the sound properties settings for everything

When the CPU in the computer or laptopoverheats then it will shut down (i.e. thermal overload) and won't boot upagain until it has cooled down. If this is the problem is not fixed then theCPU will eventually fail.
A faulty fan causes this problem or the fan and heat sink assembly are cloggedwith dust.
Check the CPU fan to see if it spins freely, if not replace the fan. If the fan and heat sink is clogged withdust the remove the dust and make sure the vents are clear and dust free. Use acan of compressed air to do this.

Have you tried Safe Mode, Last Known Good Configuration or booting to your Operating System disk

Hello.

From your description, I suspect your motherboard is problematic. Since your computer is under warranty, I would advise you to contact Dell for repair or replacement.

Go to http://support.dell.com/support/topics/global.aspx/support/dellcare/contact_us?c=us&l=en&s=gen&redirect=1 for assistance.

Hope this helps.

Hold down the power button for 10 seconds. That will hard-shut the PC. Once that is done, fire it back up, and try again. Somethimes, windows will act goofy shutting down. Especially Vista when it is left on too long without shutting it down.

Try the Google links with dell inspiron 1545 won't stay on

1. Go to support website
http://supportapj.dell.com/support/index.aspx?c=au&l=en&s=gen

2. Click on Drivers and Downloads.
3. Click on Choose by Service Tag
4. Enter you Service Tag
5. Download the Audio Drivers and Install it after the download

Check your computer bios settings. There is a power managment section. Turn off power managment or set it to os controled. Check dells support site for any acpi drivers that you may need. These are needed for suspending controls.

Hope this helps.