opening .wps files

Hello. I am new to Mac and am still adjusting. I have a question about email attachments. I receive a lot of attachments that are .wps files from a friend with Vista. I cannot open any of them. I do have Pages installed and hoped that would solve the problem, but it's still a no go. I have seen questions about other windows files and the downloads to fix them, but not any about .wps. Is there a download to help me? Thank you for your help, I may need a lot more!