help

Actually, you are not working on any 8051 development board, since you will not be able to work on any physical platform until you have managed to build any application to run on it.

By the way - are you sure you know what processor you are using? You have now posted two different processor models.

And the compiler do not just give an C318 error message. The C318 is just a short number to allow you to easily locate the error in the manual. Besides the number, the compiler also mentions the name of the file it can't open. And you have still not - despite being asked to - mentioned the name of the file.

And you haven't given us any clue that you have spent any time figuring out why the compiler can't open this file either.

Actually, you are not working on any 8051 development board, since you will not be able to work on any physical platform until you have managed to build any application to run on it.

By the way - are you sure you know what processor you are using? You have now posted two different processor models.

And the compiler do not just give an C318 error message. The C318 is just a short number to allow you to easily locate the error in the manual. Besides the number, the compiler also mentions the name of the file it can't open. And you have still not - despite being asked to - mentioned the name of the file.

And you haven't given us any clue that you have spent any time figuring out why the compiler can't open this file either.

<P89V51Rx2.H> file can not open by the compiler

i m using the NXP P89V51RD2 PROCESSOR

so how could i remove that problem

How many of my questions from my initial post have you still not answered?

Such simple questions as: "does it exist"? "does it exist where it is expected to exist"?

Have you considered searth paths? Where is the compiler expected to look for include files? Can you, by configuring the compiler, affect where it will search for include files?