Thanks for all the replies, in my original post I was being brief, I will attempt to be so here but in more detail. WIN 7 64 bit OS.
I purchased a 500GB external HDD.
Because of the information to be held on the ext' HDD, ( client details in the form of individual Word files ), I scared s*itless in the event of this ext' HDD being stolen ).
However my requirement was to encrypt my ext' HDD but if required
be able to take it anywhere with me and plug/install it in to any remote PC/Laptop to get at the data.
However due to my lack of knowledge, ( actually not really thinking it out logicaly ), it's not how encryption works, should work from a security point of view, I understand this now.
I had looked at encryption software before but found the whole thing rather pithy/wordy and confusing coupled with the fact quite rightly the PC savvy understand instructions using words like "Mount", " Volume" and so on where as I use words like, " click ", " select ", " hard drive"/ "HDD".
But I still need to encrypt my new ext' HDD.
With that in mind I looked first at Bit Locker, I read several times the instructions, I simply didn't understand them, then True Crypt
as that seemed to be a popular choice.
So I got to grips with TC with advise from others and succeeded in installing and using TC, it works fine but not the way I thought it would,----my lack of knowledge or over expectation.
Usually when you plug in an ext' drive under Windows it will be assigned a drive letter automatically unless you choose and fix a drive letter your self, which in this instance is what I did,-- I gave the ext' HDD a fixed drive letter, ( T ).
However during the process of installing TC it requires the removal of this Windows/self chosen drive letter within disk management and TC then does its own drive letter assigning every time software is used with the ext' HDD plugged in.
I can choose any letter, ( except "T" ), it's not fixed within TC.
In the event of the theft of my ext' HDD, while the encrypted data will be safe, under Disk Management the HDD/Volume can still be seen and formatted.
This surprised me, among other things.
All a thief has to do to under DM is to re-format the drive and all the data, while inaccessible/safe would be lost anyway and they get to use the HDD.
So if there is an outside chance of my my ext' HDD being recovered any data on it could be lost which to my mind kind of makes said HDD useless as a back up/storage.
Also,( my lack of understanding again ), while TC and BitLocker have portable modes, you must have, (if I understand correctly), administration rights over any PC you might wish to plug the encrypted ext' HDD in to, so if not my machine,---- not good practice anyway---- but I have only come to realize that now.
I genuinely thought I could, if I had to, plug my encrypted ext' HDD in to say a clients PC, get at their Word doc./folder, do what I had to do, un-install ext' HDD and everything would be OK.
True to a point but what with key loggers and screen capture software, not a smart idea and my understanding is TC would have to be installed on the remote PC anyway.
So a rethink I guess on my part.
I'm of two minds,---- if the ext' HDD is lost or stolen would it be best,---while the ext' HDD/data is encrypted to allow its new owner
to format the drive or----- prevent the ext' HDD from being formatted in the hope the encrypted ext' HDD is recovered and the data intact? The latter being my preference.
I'm not so much asking asking about my PC or any machine under my control but is there a way under any Windows OS to prevent my ext' HDD being formatted----- or prevent the HDD/volume being seen if used in another computer under disk management or Explorer?
My thinking was if ext' HDD couldn't be seen it couldn't be formatted, ( stupid I guess ).
So to recap, is there a way I can take my encrypted ext' HDD and use it in any PC, ( not under my control ), and the data safe.
And/or in the event of theft can I make my ext' HDD non-formatable to others?
Simple instructions would be much appreciated failing that a barn full of support if I undertake the advise given.
Should I really be re thinking this, how I wish to achieve all/any the above? again advise would be welcome.