I pushed the German language instead of English, I cant proceed

There should be option to select language with its settings page. Refer its user manual for details. Gopakumar Gopalan Google

You need to go to settings and change your language to english.
However as all the buttons are in german this may be a bit difficult.

If you don't have a manual which describes each button feature go to the mio website and download the manual from the support function.

Hi I presume your in Australia?? Go to the web site below and download manual for your satnav. Find english instructions on how to change language and see if you can follow the pictures and change to Australian
http://www.navman.com.au/car-gps-devices/user-guides/

• Press TOOLS (the spanner icon in the bottom right of the screen with WHERE TO and VIEW MAP)
  
• Press SETTINGS (The spanner icon) or LOCALE (the blue icon) whichever your satnav has
• Press LANGUAGE (the lips icon)

This takes you to a screen with 3 items on it; VOICE, TEXT LANGUAGE and KEYBOARD

Press VOICE and select the name of an English speaking person to change the voice instructions to English.
Press TEXT LANGUAGE and change it to English or American English if you're in the USA

The TEXT LAGUAGE should be showing DEUTCH beside it (the German word for German)

This should solve your problem

In the menu, you should find the settings for language.

Now, If you don't speak German, this can be a problem.

If you use your computer to translate, you can do it.

Go to http://babelfish.yahoo.com/ and select the languages as required (German to English). Enter the commands you see on the TomTom, and navigate that was until you see the language settings.

uder the base of the unit you will see a small hole about the size of a pen this is the reset button get a pen or similar item insert the nib into the hole and press the button this should reset the unit

Einstellungen - Settings
or Werkzeuge - Tools

Sprache Einstellungen - language settings

Englisch - english

First of all the language was Finnish and not German. I managed to get a translation from Finnish to english for the word  kieli (Language).  Then i went to the system menu and selected kieli, then englanninkieli then pressed enter, this changed the language to english. I did not have to do a factory reset. Thank you for your trouble.
Regards Noel

If you can get to your settings area it looks like a little gear. Go 6 options down and touch it and you should be able to change it there. The user manual is in the link below if you need more technical information.

http://www.navman.com/in-car/3294/Australia/Navman-Australia/Our-Products/Current-Products/S150/

I solved the language problem by selecting the settings icon and then fumbling my way through the German instructions until I found something that looked like the language selection and yep, it was so it was easy enough to change back to English.