I am pretty sure that Uncle Bill Gates has not taken the trouble to write a special version of Windoze for the Portuguese, and you should therefore have little difficulty in changing it over to use English instead. Indeed you can have your choice of U.S or U.K. English to boot! The only things to consider are the power supply voltage, but most power supplies accept from below 110 volts @ 60 Hz to over 240 volts @ 50 Hz these days this shouldn't be much of a problem either. The only other thing to watch is the keyboard - if you wanted Shift-3 to print the U.K. puunds symbol for example then it will probably do this when U.K. English is requested, but will be engraved with the # symbol. You may well have similar trouble with the Euro symbol - cure - buy a local keyboard!
P.P.