sorry if I annoyed you guys and ijack. I wasnt addressing my frustration to you people or this forum..actually I got fedup of searching through various sites and forums for a solution and its kind of irritating there are so many utilities like folder lock etc making big claims out there and none mentions of the inter OS risk neither is it clearly written on a single place that win permissions are windows limited. It then also annoys coming to realise after months that a nosy co-user likely be using ubuntu only to sneak into my personal folders all the while.
another cause of confusion, I asked same in another forum a while back and got a slightly different answer:
"" If you have restricted access to some files and folders by manually editing permissions, then it's possible that access will be denied by the second Windows and the only possibility to access the files would be by taking ownership, which you can do by logging in as an administrator.
Similarly, Ubuntu will be able to edit NTFS permissions. The permissions themselves are not part of the registry, so whatever Ubuntu does will stay with the files. But by taking ownership in Ubuntu, you will deny yourself future access in Windows.""
""Well, if others are using different OSs on the same machine, then there is nothing you can do to prevent them from viewing your files, except for encrypting, for example using BitLocker. Then changing ownership will not help them, since they still would need to know your password, and likely Ubuntu will not know what to do with such a file at all.
Now, if someone does access your files by changing ownership, then you can clearly see that - the owner has been changed. I am not sure whether the time stamp will be preserved, i.e. whether the "date accessed" column in explorer will be modified as well, Windows is not very consistent on that one.
So, I would guess that if your permissions are the same, you're still the owner, and nobody in your household has super-hacker skills - then your information should be safe""
From the reply it seems that - ntfs permissions are common and will need changing them in ubuntu to gain access which inturn will effect access in windows.
sadly I was hoping this be true as although changing permissions is a trivial thing but it will be a relief to know that my files are still not sneaked into as I can still access my files without problem.
I am willing to use EFS but the limitation with encryption I found on the net again is that although it wont allow anyone to use/move the files inside the encrypted folder but still allow to explore its subfolders and filenames. please correct me if I am wrong.
additional info welcome.