The Intel® Server Board SE7520BD2 reach product discontinuance in January 2006. There is rarely any validation for products after product discontinuance. In addition, the SE7520BD2 is a server board and no desktop board operation systems were ever validated with it. See:
With Windows 7, or Windows 2008 R2 the most likey thing you'll find is that the server board hardware is not supported by the Windows 7 operating system kernel. However the only way to know for sure is to try it. Intel hasen't tried and therefore can't tell you yes or no.