Check out your exchange/return options with Best Buy as recommended by @Cecil. If this doesn't work out, continue reading...

It sounds like you've deleted your ASUS Recovery partition and have not created the Recovery DVD's. You will be able to re-install Windows 7 once you delete the current GPT partitions on your HDD and create MBR partitions. http://answers.microsoft.com/en-us/windows/forum/windows_7-windows_install/windows-cannot-be-install... will get you going with this procedure.

If you get a new system, learn from your mistake and create the Recovery DVD's. Read this thread:http://rog.asus.com/forum/showthread.php?16645-Step-by-Step-Using-ASUS-Recovery-DVDs-to-Restore-G75&.... The Recovery DVD's will be helpful to return your system to stock condition should you decide or need to return it. Otherwise, you're not missing much. Like most, you'll probably enjoy the clean Windows installation better. AND you still have the option to add any of the ASUS Bloatware apps you desire...

aonath wrote:
I have a Asus G75VW-BBK5. Yesterday trying to install windows 8 on a new partition i press "format" by mistake on the partition called "System", now when I turn on my notebook I get a message saying: "Reboot and Select proper Boot device or Insert Boot Media in selected boot device and press a key ".

Well returning your system ( as Cecil noted ) might be an option.

If you have a 64 bit Windows 7 SP1 install disk ( can find download from microsoft digital river ) that might possibly work for repair ( doubt it but worth a try ) ... it would need to be SP1 to understand UEFI environment ( not the base original Win 7 install ).

If you create a bootable CD using MiniTool Partition Wizard 7 you should be able to delete all the partitions on your existing drive then head into a fresh Win 7 SP1 install.

If you go for the fresh install choice and keep your machine instead of return/exchange you should purchase from asus a set of recovery DVDs. The problem with sticking an ISO out of the recovery DVDs that people burn themselves on their machines is that it carries along the Win 7 installed OS keys ... guessing the factory supplied DVDs would prompt for a valid Win 7 registration set of numbers ( which you have on the bottom of your laptop ).

Bottom line: People should update to latest asus recovery utility and burn themselves a set of recovery DVD's immediately before starting to do anything else with their system!

Good luck and keep us posted!

If you can't return/exchange your g75, then your best bet is to do a clean install of Win7 as dstrakele and john_from_ohio are suggesting while at the same time requesting a set of recovery DVDs from ASUS.

ASUS wants $50 for the Recovery DVD's. Personally, I don't think that is a wise expenditure. There is no guarantee they will work. I spent some time trying to help a user restore his system with the purchased DVD's and he would immediately get an error which we were unable to resolve - $50 down the drain. He ended up downloading a Windows 7 ISO and creating his own Windows installation DVD to successfully perform a clean install.

So in my personal opinion, if you've deleted the ASUS hidden Recovery partition and forgot to create the Recovery DVD's - forgetaboutit! Do a Windows clean install and use Windows Backup and Restore to create a Windows System Image that you can use just like (in fact a LOT easier than) the F9 Recovery or Recovery DVD's. If you absolutely must spend $50, get Acronis True Image Home to simplify your backup and recovery needs.