External drive not appearing in Windows Explorer

Hi,
Although I am completely new to Macs, have installed Parallels on a MacBook Pro and everything seems to work fine. Have also installed Windows XP Pro.
One thing, however, puzzles me. On my pc when I connect an external hard drive to a usb port it appears in Windows Explorer. On the mac, however, although the drive appears on the mac desktop, when I switch to the Parallels desktop and open Windows Explorer the drive does not appear there.
Why is that?
Regards
Brian

 

1. Make sure drive is formatted as NTFS or Fat32
2. Use Shared Folders as described in Parallels Desktop for Mac user guide from http://www.parallels.com/en/download/file/doc/Parallels_Desktop_for_Mac_User_Guide.pdf on page 207

 

All drives must be NTFS or FAT32? As it is, Windows Explorer currently lists my HFS+ formatted Lacie drive (FW800) yet none of the other 3 other internal drives (all also HFS+) with the "Share Mac OSX folders with Windows" checked. I can map to them via the "User-defined Mac OS X folders" area, but my PC programs that use files by reference are very unhappy when the drive letter changes after an XP reboot. Basically, it breaks the books I design that pull in photographs by reference.

 

Hi folks,
Sorry for the delay in replying. Thanks very much for your help.
Brian