Unable to move images?

[onomastikon]

I'Ve successfully made a few .mdf files with DT, and have been able to get them to work. But I have been unable to archive them to my external hard drive, a fairly standard Toshiba device, which is about half full (650 GB). This is the first and only time I receive the error message: "the file is to large for the target system" (I use a German version of Windows 7 so the message is in German, sadly). The image files I am trying to move are between 7 and 8 GB, nothing bizarre or unusual, I have many files on that device that are larger.
What am I not understanding?
thank you

[Blazkowicz]

Your external HDD is most likely formatted with FAT32 which only can handle file size up to 4 GB. Also these images shouldn't be mounted at the time of movement.

Run the following command:
convert DRIVELETTER /FS:NTFS /X /NoSecurity

Exchange DRIVELETTER with the drive letter of your external HDD.

[onomastikon]

Thank you very much for the speedy reply!
Two follow-up questions if I may:
1. How did I already get some 8-gig images onto that drive last year?
2. Where and how do I run that command exactly? I am a computer idiot, but CAN follow directions well if spelled out for me. Thank you very much!!!

[Blazkowicz]

Press Windows Key+R -> cmd -> then enter above.

[onomastikon]

Thank you.
I tried this and received "Invalid Drive Name" (I typed in "I" since this was what was given in the explorer)

[Terramex]

I typed in "I" since this was what was given in the explorer

You need a colon after the letter.
But before converting:
Which file system is shown in the properties of that drive/partition ?
The other/older large files were copied in Windows Explorer and are fully functional ?

[onomastikon]

You need a colon after the letter.
But before converting:
Which file system is shown in the properties of that drive/partition ?
The other/older large files were copied in Windows Explorer and are fully functional ?

Thank you.

- I'm not exactly sure what "file system" means, but when I right click and select "properties" it does say "FAT32" somewhere.
I hate having to translate back and forth from the German, but is this what you mean with "system"?
From what I can gather, the other larger files WERE copied in WE (it's the only thing I use) and I believe they are fully functional (there are also .mds amongst them). I do not remember getting an error message regarding file size last year.

One thing I note is that when I plug the HD in to the USB, it frequently asks me first if I want to "repair" it. At first this worried me, but I usually just close that window and ignore it and nothing seems to be of consequence. I can still use all of the files on that HD without a problem.

thank you very much for your help

EDIT: Sorry, I am wrong, all of those .mds and other files are actually UNDER 4 GIG! I was mistaken, sorry! Blazkowicz is correct.
Is there any danger in doing what is suggested (screwing up the HD, making some files unreadable)?
Are there any empty spaces in the bit of code your wrote
convert DRIVELETTER /FS:NTFS /X /NoSecurity (<-- empty spaces after "I:", or "NTFS" or "X" ??)

[Blazkowicz]

I haven't had any file loss when I converted a FAT32 HDD to NTFS.

Just type the command as I wrote it, with DRIVELETTER be e. g. I:

[onomastikon]

When I type in the command it asks me to specify a "volume". What must I enter (as a value)?
Thank you

[Blazkowicz]

Volume is the drive letter.