Ext. Hard Drive Not Recognized After Plugging Into a Mac

[Bigruckus]

I have a USB external hard drive that I unplugged from my pc and plugged into a Mac to transfer some files from. The Mac recognized the drive and files but wouldn't let me put any files onto it, stating it was read-only. Oh well, so I unplugged it and now my pc (and others) won't even recognize the drive, giving me a message "one of the usb devices attached to this computer has malfunctioned and windows does not recognize it." Oh crap...

Here's my question - is it just a question of drivers or did that skanky Mac put some stink on the drive that is irreversable? There are files on there that I'd like to recover if it is indeed messed up now. How do I reverse this Mac curse?

Thanks!