VB.net Read file

I am learning computer programing in college and am trying to advance my knowledge outside of class. I am looking to make a program that will read the data inside a file and output it to a textbox on the form. The data that i would like to be displayed on the first line of the file and is about 10 characters long. The file that i want it to read does not have a extension but when opened with wordpad it does have readable text inside. After it being read and output to the textbox I would also like to be able to edit it by typing in a second box a string that will replace the data in the file currently. Could anyone help me to get this to work? Thanks.

*Update* I actually figured it out and made the public function but now what i am trying to do is select where the file is stored at because the file will be stored in one of two locations. It will either be stored on the C: or D: drive. How would i get the program to locate which drive it is stored on then execute the necessary function. Thanks.