Many versions of Linux can read the NTFS, which is used by Windows.
But Windows does not read the Linux file system.
What do you want to do?
Which version of Linux?
Which version of Windows?
You can, if you want, create a small FAT32 partition and share files between the two systems. If something goes wrong, it souled only affect that partition.
Both Windows and Linux can read Flash drives.So you could use a Flash drive an not have to alter anything. You can get a&GB flash now a t Wall Mart. So it is hardly worth the effort and risk of altering your partitions on the Hard Drive. Or by two of them. and backup your most important data.