300e5c which key of boot menu

can you click on f12 before it goes to boot password?
The F12 Boot Menu allows you to choose which device that you would like to boot the computer's Operating System from by pressing the F12 key during the computer's Power On Self Test, or POST process. Some notebook and netbook models have the F12 Boot Menu disabled by default.
If this sounds like your problem then try this:
If this sounds like
To enable the F12 Boot Menu:

1. Restart the computer.
2. Press the F2 key to enter computer's BIOS Setup during Power-On Self-Test, or POST, process while the Acer logo is being displayed.
3. Press the Right Arrow key to select Main
4. Select F12 Boot Menu
5. Press the Enter key
6. Select Enabled
7. Press the Enter key
8. Press the F10 key and then press the Enter key to save the changes and restart the computer.

Note: Not all Acer notebooks or netbooks have the F12 Boot Menu feature. Computers that do not have the F12 Boot Menu feature will not be able to enable the feature within the BIOS. I hope this works for you if not, then the problem is obviously not the boot menu. Go to Acer support for more help

The hard drive may be failing, or just the OS or hard drive corrupted. If you have files that you do not want to lose, you could try this... Pull the hard drive out, and use a "USB Hard Drive Adapter" to connect the hard drive to a friend's computer, and save all the personal files (documents, pictures, etc.) you can to a folder on the friend's computer or an external hard drive.
Then, you could try to do a Factory Restore on the computer, and if that works, copy your personal files back to your newly restored computer.

Press DEL to get to your bios options then disable fast boot. This will allow you to hit the appropriate key to enter the boot menu.

Restart your computer repeatedly tapping the f8 key to enter safe mode while the screen is black once in safe mode where the only things working will be your keyboard and mouse allowing you to attempt to repair your computer
Windows Advanced Options Menu
Please select an option:
Safe Mode
Safe Mode with Networking
Safe Mode with Command Prompt
Enable Boot Logging
Enable VGA mode
Last Known Good Configuration (your most recent settings that worked)
Directory Services Restore Mode (Windows domain controllers only)
Debugging Mode
Start Windows Normally
Reboot
Return to OS Choices Menu
Use the up and down arrow keys to move the highlight to your choice
select safe mode with command prompt
Click start run type cmd press Enter
black screen should open DOS mode
this will vary depending on your operating system
type in net user username
For eg. If you want to change administrator password , type net user Administrator
It will prompt you to enter the new password.
Enter the new password and the password is changed
http://wiki.ljackson.us/Control_Userpasswords2
if this fails you will need to
Select safe mode with networking to download
you could download all of these or just one save them to a usb drive for later use if one fails to remove the password
Windows Password Recovery Basic
http://majorgeeks.com/CmosPwd_d239.html
A CMOS BIOS password recovery tool
Editors note: This tool should only be used by experienced computer users.
Please see the enclosed read me if you would like to run it from Windows.
Failure to follow instructions (from Windows) will cause your anti-virus to flag this as a virus.
http://majorgeeks.com/Dr._Freeware_System_Utilities_d6416.html Dr.Freeware System Utilities which includes data recovery software, data backup, password reset tools for Windows helps you to maintain your system. Dr.Freeware is freeware, you can download and use it for free.

.Abit did not add the BIOS post to the manual.

Watch the BIOS post, most all motherboards have the hot-key menu at BIOS post.

If for some reason the hot-key is not reported on BIOS post, then you hit the DELETE key and enter the BIOS, Advanced BIOS Features Setup Menu and set what hardware you want to boot first, under Hard Disk Boot Priority, set First Boot Device

F12 Or DEL

there should be a boot menu command at start up just like you entered the system bios, i believe the e machine boot command is F12 that will give you the opportunity to boot from what ever you want on that boot only. so in your case of course you would scroll down to cd and hit enter. press any key to boot hit any key and boot.

ESC (Escape) on the keyboard should be the Boot Menu key, means you have to tap the ESC key once you press the power button to switch on the Machine and select the boot device from the options available.

If ESC key doesn't work, then try F2 or F8 or F12 (these are all the boot menu keys for Asus motherboards and Laptops).

Let me know if you need further help, but with more details about your problem.

Good Luck.
Thanks.

Try Esc or F4 to access One Time Boot menu in Samsung computers

F12 is the Dell boot menu key.