How to choose OS at startup?

Download the utility QuickBoot

From http://support.apple.com/kb/HT1310:

This startup volume selection is temporary. To set the default startup volume for your Mac after your computer is running, open System Preferences and choose Startup Disk from the View menu (in Mac OS X) or open the Boot Camp control panel (in Windows).

No need to download additional software

Boot Using OPTION key:

1. Restart the computer.

2. Immediately after the chime press and hold down the "OPTION" key.

3. Release the key when the boot manager appears.

4. Select the desired disk icon from which you want to boot.

5. Click on the arrow button below the icon.

SalahKun wrote:

is there any way to make an menu appear every time I turn on my macbook for choosing the bootcamp partition or the mac os one ?

i dont like pressing alt everytime 😟

Sure, you install a virtual machine software like VMFusion or Parallels Desktop, the read the instructions how it copies the present BootCamp install into a file in OS X.

Now you run Windows in a window on OS X, switch back and forth between them or even *gasp*, merge the two operating systems, appearing almost the same.

The only thing you use BootCamp for is heavy duty CPU or graphic intense 3D games, everything else you use the virtual machine Windows instead. 😉

Windows in BootCamp or Virtual Machine?

rEFIt 0.14

SalahKun wrote:

but does it work on mac os x lion ?

NO!

rEFIt hasn't been updated in AGES, only works for 10.6 machines.

DO NOT INSTALL ON 10.7 or 10.8!!

http://refit.sourceforge.net/history.html

http://roaringapps.com/apps:table/tags/_r/index_tags/_r

shows it campatible with Lion and Mountain Lion.

To do what you want requires a EFI firmware modification as EFI loads before the operating system does.

This area of the machine is rather sensitive and Apple is prone to creating changes there without consideration for other software as they feel it shouldn't be there in EFI in the first place.

EFI is dangerous in the scope that a malfunctioning or malicious program can be installed in there and can run even before OS X has a chance to boot up or in between OS X/Recovery and accessing hardware.

In order to clear EFI in case it refuses to load may require wiping the entire drive of everything and reformatting it anew from a outside bootable source if the EFI firmware restore cd's won't work.

Also anti-malware methods of OS X and software don't work in or on EFI.

All I can say is you best really trust what you install into EFI, your taking a big risk it will break it if it's not updated or when a Software Update occcurs.

I think virtual machine software is a better solution as you will only be booting into Windows BootCamp for heavy CPU/Graphic needs, everything else in Windows you will be doing in a virtual machine Windows copy instead.

I have no idea. It doesn't really have to. It needs to replace the standard boot loader.

Here's a possible alternative to rEFIt you can try:

Boot Runner.

I know nothing about it.