2 TB, if you want to use any version of W7 that has the built-in Backup and System Image suite, such as W7 Ultimate, or Professional.

 

You can only use a 2 TB and less capacity hard drive, or USB external drive to use this W7 built-in feature.  It has to do with W7 not correctly parsing the File System, and then can not write a file to the greater-than-2TB disk drive. This is well documented upon the Net.

 

So...the bottom line is...if you wish to purchase a HD (whether internal, or external) you can use with no problem drives such as a 4 or 6 TB drive...with the only catch that you can not create a System Image on it.  I found that out the hard way...bought a 4 TB MyBook for this purpose, and along with wanting to store other files.  A System Image takes up about 900 MB's for my system. So..after reading why I kept getting a File System Error when trying to create an internal System Image, and why this was happening to me, and a lot of others...I went out and purchased a 2TB MyBook..and had no further problem creating a System Image within W7 Ultimate. So, that's the story...and now you are aware of the 2TB limit.

 

Just to clarify...W7 can, and will read/write to a drive greater than 2TB...yes...but will NOT be able to create a System Image on a drive greater than 2TB, max.  I have not tried creating a System Image with a 3rd Party app.  That might do it...for we are only talking about the back-up utility baked into certain versions of W7. I just wanted to make that clear...

 

Cheers,

 

Ses

What happens if you create two 2TB partitions on your external drive ?

What happens if you create two 2TB partitions on your external drive ?

Not sure about that one...it might work.  I never tried that, and nobody on the Net who has a 3 or 4 TB external or internal brought that up as a solution to the 2TB file system barrier.  Being that I bought a 2TB, I'm going to keep my 4TB non-partionied...but anybody that wants to try your suggestion...would be a good feed-back. I would think though, Mad Dog...that someone would have tried that...before I started to read up about it.  Do a search for yourself, and you can read all about it.  

 

I guess that most people do not go past a 2TB purchase, so never even knew that there is a glitch....and a catch-22.

What happens if you create two 2TB partitions on your external drive ?

 Should Work

You can use a >2.2TB hard drive as a system boot disk for windows 7. But there are a few requirements:

 

1. 64-bit version of Windows 7

2. Computer needs to have a UEFI compliant BIOS.

3. Hard drive using a GPT partition, not MBR

Exactly what woodreau said, I experienced the same problem and solved it by creating a GPT partition.  It now sees the full 4TB.