Toshiba satellite pro L450-EZ 1543, is showing a curser blinking with black background, its not booting up, how to fix the prob ?

Both. Install from Windows and choose drive. It will create a partition on drive chosen. Plus you can choose size partition during setup.

Restart your computer
During the boot process you will see on the screen to press a certain

key to enter setup usually the Delete or F2 key
this will vary depending on your computer and operating system

Press and hold that key during the boot up process to enter BIOS using the arrow keys load failsafe defaults or load optimized

defaults press escape then press f10 to save to cmos to restart

hope this helps

This indicates hard drive issues, or windows files have been corrupted. If you have a backup disk try and load windows, no change! have the hard drive tested for possible replacement.

Yes you can DIY.

Toshiba A45 replacing hinges would be similar to youe model laptop.

http://www.irisvista.com/tech/laptops/ToshibaA45/Satellite-A45-remove-hinges-1.htm

you might have to physically unplug the leads for this cd/dvd then plug them back this should activate the found new hardware wizard or
you might have to uninstall then restart your computer then reinstall your DVD/CD then reinstall the driver for this device
if your computer came with a motherboard disk the drivers could be on it
click start control panel administrive tools computer management device manager scroll down cd dvdrom drives if you see a yellow question or exclamation mark? ! or a red x right click you will need to update the driver or
select properties general troubleshoot, select driver click to reinstall drivers click update driver
if you dont have motherboard disk you will need to download the drivers
http://download.cnet.com/dvdram-en-20071009085435-zip/3000-2110_4-172943.html

http://download.cnet.com/dvdram-en-20070907111350-zip/3000-2110_4-170034.html

http://download.cnet.com/dvdram-win2k-5025-en/3000-2110_4-172950.html
hope this helps you

makes ure you have selected internal display, which is fn key near shift and usualy f4, although it should have a blue picture of the laptop and a screen on the key.

OS is corrupt...reinstall OS using the original Windows CD

TRY START UP IN SAFEMODE ( USING THE F8 KEY ) KEEP PRESSED DOWN WHILE ON START UP OR RESTART ! THIS WILL SHOW A DIFFERENT SCREEN AND YOU SHOULD BE ABLE TO SORT IT OUT ! IF NOT THEN TRY PRESSING CNTROL ALT AND DELETE TO BRING THE CONTROL MANAGER UP AND AGAIN SOMETHING COULD BE RUNNING THAT SHOULD NOT !

To avoid laptop overheating, follow the information from this link.

Return it to the store and let them fix or exchange. Sounds like it was a demo unit that they set a password on.