Can't reformat acer travelmate 5720 help pls

Hi everyone, I'm kind of desperate. I have a problem on my acer and I can't even turn it on, I mean I can't reach the desktop, when I turn it on it sends me to the black screen where I can choose whether to start windows normally or in safe mode but neither of them work as I get a blue screen after a little while while there's the windows logo. This has happened to me before on an IDENTICAL computer and I solved this problem just by reformatting it, unfortunately it's not working now. Am I doing something wrong? I tried the following combinations clicking them as soon as I turn it on (as soon as I push the "on" button):
F11 (it does a noise but as soon as I release it sends me to the black screen stated above)
F10, CTRL+F10, CTRL+ALT+F10, Altgr+F10 (nothing happens, only in CTRL+ALT+F10 it started doing the noise that it did when I was holding F11 but as I released same thing as F11, it sent me back to the black screen, I tried again but nothing happened so same as F10)
F8, F5, CTRL+F5 and then F8 (It just sent me to a sort of more advanced black screen where I could choose more options but no reformat).
Any other combinations that could let me reformat the computer? Basically I want to delete everything and I guess I'll reinstall it later, I want the computer to be as it was when I first bought it, as of now I don't really mind losing all the data, I just want to get the computer back. Please help me, I'm desperate.
P.S. Sorry for my bad english, I'm not english but if something isn't understandable I'll try to write it in a better english if I can. Thanks.