I have a personal computer that I use for studying, but my older brother saves folders that have songs and other things that are not Islamically lawful. I am embarrassed to tell him not to do that. Does the fact that these folders are on my personal computer mean I will be held accountable for them?

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.

Trying to change the evil is your duty because this is your own computer and it is not permissible for you to help someone else to commit sins on the pretext of being embarrassed. First of all, you have to delete those files as it was narrated by Abu Sa‘eed Al-Khudri, that the Prophet, sallallaahu ‘alayhi wa sallam, ordered the one who sees an evil to change it physically with his hand if he was able to do so. If he could not, he should change it by his tongue (by advising and/or condemning), and finally by (detesting it with) his heart, and he, sallallaahu ‘alayhi wa sallam, informed that this is the weakest level of faith. [Muslim]

You can change this by your hand since this is your own personal computer and you are responsible for it. If you did not do so you would be an accomplice in this sin. Allaah Says (what means): {And cooperate in righteousness and piety, but do not cooperate in sin and aggression.}[Quran 5:2]

 Moreover, you should love for your brother what you love for your self so that your faith would be complete. How can you be satisfied with the fact that you brother would go to Hell, while you would be rescued? Therefore, you should call him to Allaah and point out how these files are harmful to him. You should also use any possible lawful means to guide him to the right path. You can pray to Allaah The Almighty to guide him, accompany him to the meetings held by righteous people perhaps he would guided. You can seek the help of experts in deleting those files as this is very easy for those who deal with computers.

Allaah Knows best.