Linux filesystem
 

how to access linux filesystem with read & write access from windows, is there any free software

There are about 30 supported filesystems on Linux. Which one were you interested in accessing?

There are some softwares which will allow you access linux partitions from windows. But it's not good idea to get write access on linux partitions from windows. If you want a common space between two OS's, then I suggest you to make a separate partition in windows with FAT or FAT32 file system. Mount this drive in linux. Now you will get write access on this partition from both OS's. It's just a suggestion. There may be other ways, wait and see, you may get many replies. :)

If you are wanting to access the linux from the same pc. meaning both linux and windows are on the same HD then do as raju.mopidevi stated. Its the same principle as using a thumb drive, but if you are using two different pc's one with linux and one with windows then look into running SAMBA on the linux system.