Setting a path and Classpath for Java

Dear

Appreciated for your quick answer for my first Question I am Glad.My second question is about setting a classpath in Java.

Q)I have installed windows2000 on my D Drive and XP on C drive I installed JSDK 1.5 on D drive I need to setpath and classpath when ever I run program it is saying cannot read the (F1.java)file name?

Reagards
Faziurrahman