***para que pueda usar***
(After para que, the subjunctive must be used because there is a change in person. So you are asking, "Does someone know a code so that I can [...]?" The first subject is the someone and the second subject is yourself. It is like when a person says, "Quiero que hagas mi tarea." [I want you to do my homework.] The first subject is I and the second is you doing my homework. Hopefully that was explained well.)
Lo más facil es formatear tu computador para que puedas tipear la tilde. O sea, es lo que hago yo y funciona muy bien. Nunca he tenido problemas, pero hay que acostumbrarse a usarlo.
Enlace para la página que explica todo.