Hi, I've been all over the net trying to resolve this issue, and found many hotfixes, downloads from Microsoft and manufacturer, but to no avail. My external drive was recognized for the first month. Then, very suddenly, Windows 7 doesn't recognize it. It sees it, but prompts a "Need to Format before first use". It has 300G already used with valuable info. Tried moving the external hard drive to our home PC with Windows XP and the same "Need to Format" message is prompted. If I hook it up on my wife's MAC, I can see the data. Now I have read that this is a known issue with the 64bit version of Windows and external drive. I have already all the KB976972 and KB977074 download fixes from Microsoft. I have also tried to uninstall the drive, unplug it, turn it off, restarting Windows, and plugging back the drive, but I have the formatting prompt again. And if I choose to not format, i have an error message DATA ERROR (CYCLIC REDUNDANCY CHECK). **This does not seem to be an issue regarding only the WD drives but all drives** Called WD tech, and it was useless. Does anyone have a fix? A link to share? An idea? I'm running Windows 7 Ultimate 64bit on my HP Pavilion a6418f. Thanks for any help...! E.