Error starting Nios II IDE

Hi all,

When I start Nios 9.0 IDE, it gives error as shown below. I don't understand it because I had installed Quartus II 9.0 web edition which I downloaded from altera website. Please help. I had launched Quartus II before Nios IDE but still show the same error.

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The configured Quartus II version [9.0sp2] does not match the current Nios EDS [9.0]. Install and launch an Instance of quartus II version 9.0 before continuing.

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Also, Can I simulate Nios application software C/C++ program without using the actual board? In other words, can I simulate my program without downloading the program into the FPGA board.

Thank you in advance.