error while i try uploading

i am a complete beginner to arduino. i have arduino uno board with atmega 328p.
when i tried the blink program i am getting the following error

java.io.FileNotFoundException: C:\Users\ahlawat\AppData\Local\Temp\build4085660763111043355.tmp\sketch_jun01c.cpp (The system cannot find the path specified)
at java.io.FileOutputStream.open0(Native Method)
at java.io.FileOutputStream.open(FileOutputStream.java:270)
at java.io.FileOutputStream.(FileOutputStream.java:213)
at java.io.FileOutputStream.(FileOutputStream.java:162)
at processing.app.debug.Compiler.preprocess(Compiler.java:1217)
at processing.app.debug.Compiler.preprocess(Compiler.java:1177)
at processing.app.debug.Compiler.compile(Compiler.java:354)
at processing.app.debug.Compiler.build(Compiler.java:116)
at processing.app.Sketch.build(Sketch.java:1162)
at processing.app.Sketch.build(Sketch.java:1137)
at processing.app.Editor$BuildHandler.run(Editor.java:2032)
at java.lang.Thread.run(Thread.java:745)
java.lang.NullPointerException
at processing.app.debug.Compiler.adviseDuplicateLibraries(Compiler.java:442)
at processing.app.debug.Compiler.build(Compiler.java:123)
at processing.app.Sketch.build(Sketch.java:1162)
at processing.app.Sketch.build(Sketch.java:1137)
at processing.app.Editor$BuildHandler.run(Editor.java:2032)
at java.lang.Thread.run(Thread.java:745)

what i am doing wrong
arduino showing on serial port COM4

it's solved... just copy it to the c drive and no other drive.. the path specified is for c drive only that was the problem..