All Folders now show up as *.lnk on Win 7 Machines

It could be a virus. Who knows. I have never seen this behavior. You could of done a copy, where it just copied the shortcuts (.lnk) files, like if you drag and drop and hold the ALT or CONTROL or SHIFT key it has the option to make shortcuts aka lnk files. If you make a new folder and put files into it, does it turn into lnk files immediately? does it take a while? or does it not happen anymore? Can you use a program like TreeSize on a mapped drive location to see where most of your size is allocated to. See if your folders are there. The virus could be on your Windows side thats just using mallicious attacks on your mapped folders. mmm Maybe try to change the password of your main users that are connecting, if your using guest, try not to use guest.... Also if it is a READYNAS issue, try doing an OS Reinstall. After all that if nothing works, call in for support you might have an escalation of an issue, or it might honestly be a virus in which case if its on the windows side, we wont really be able to help. Try running an intense comprehensive test on your full system.