The missing files were found on his computer, but he claims he has nothing to do with it.

has 是动词 have 的第三人称单数现在时形式，表示"拥有"或"经历"。 nothing 是代词，表示"没有任何东西"或"无关紧要的事物"。 to 在这里是不定式符号，用于连接动词 do。 do 是动词，基本意思是"做"或"执行"。 with 是介词，表示"与...一起"或"关于"。 have nothing to do with 是一个固定短语，意思是"与...无关"或"与...没有联系"。