Why can I only use 2.48 GB RAM in Boot Camp (Win 8.1 Pro, 64-bit)?

I really don't understand why my iMac is acting so weird. Used Rufus to make a bootable stick, it doesn't show when I boot.

I was able to burn the CD as suggested (so the superdrive is really weird, why can it read CD's but not DVD's?) but the superdrive doesn't show as a boot option.

There has to be another way. I found this guide

http://www.intowindows.com/how-to-install-windows-8-1-on-mac-without-boot-camp/

There has to be a reason why I don't even get to the point where I see the efi boot option and the Windows boot option after creating a bootable USB stick.

I will try that but with my iMac (mid 2011 model) it seems to be a problem in general to boot from a USB stick. I made a bootable stick with RUFUS and it didn't find it, do I have to use the bless terminal command again?

Still getting the NO BOOTABLE DEVICE error. It seems there was some kind of disagreement about whether the info.plist needs to be modified or not. I know my iMac was booting from USB before but I don't know how to get back there. When it was booting from the USB stick my problem was that it couldn't install Windows because the hard disk was not formatted correctly. Now I can't even get back to that point.

1) 2 weeks ago it did... when you suggested to boot Yosemite from a stick and then start the whole process.

2) Please see... see what? It seems there is something missing. It's not that I WANT to modify my info.plist, I just wanted to know whether it's necessary or help me in any way.

I'm still wondering how Maubaraf (that's from a previous link you sent me) was able to use DISKPART, format it as fat32 and then copy the files from a mounted Windows 7 .iso to the stick. Like Windows 8 the Windows 7 file is too large for a fat32 partition, what am I missing here? Why is that not mentioned there?

I had the same idea, I tried 3 different USB sticks. The most promising suggestion to me is still the small boot partition on the internal hard drive - when you suggested that you said I should format it fat32 or exfat - today when we were talking about the USB sticks you said NTFS - so was it wrong to format the small boot partition with fat? (Though I'm almost sure I tried NTFS just out of curiosity)

Doesn't work, none of my 3 USB sticks shows up. That is more than strange, don't you think?!

Btw - I came across Winclone and read: Migrate external Windows system to Boot Camp

Does that mean I could migrate the Windows from my Windows laptop to Boot Camp?

and on the Windows laptop I need to run SysPrep which creates the image file?

Since I'm still entertaining other options: How come that I can modify my info.plist (from the BCA) and it always results in BC to crash though I run the

sudo codesign -fs - /Applications/Utilities/Boot\ Camp\ Assistant.app

This still results in "Boot Camp Assistant quit unexpectedly."

About the sysprep procedure. It requires to get the hard disk out of the laptop which I would prefer to not do.

I was wondering whether I can install a second Windows on the laptop on the external USB drive and then sysprep it and then connect it to the MAC afterwards.

I am sorry, that was my bad, obviously it's not a good idea to leave a copy of the original info.plist in that folder, in terminal it said:

/Applications/Utilities/Boot Camp Assistant.app: unsealed contents present in the bundle root

After removing the file it works fine. So I will continue experimenting but if all else fails - are you using Boot Camp on your computer? Or would you be willing to install Windows / Boot Camp on your MAC and then Winclone it and send it to me (I have a pretty big Dropbox for example)? I'm out of options, it's nice to try and learn new things but at some point I would actually get it done.

oh, whatever time you need.... that would be awesome, no rush please, I appreciate all the time and effort you spent to help. I found many other of your comments and help in different threads, thank you for your time.