Dvd disk formated like usb flash drive, unreadable

[wildybill]

hello, this is a relatively basic question but it has me baffled.

the problem is that i have 2 disks(dvd-r), exactly the same. both with files saved on them from my brothers pc in usb format.

one disk i can open, the other... i cant???

can anyone explain what is going on here?
the ONLY difference between the disks is on one he added the files, then he added some more, while on the other he just transfered the files the first time.

the one i cannot open is the one where he made 2 transfers, and what it seems to do is make my pc think the disk has 0 bytes of free and used space, 0 bytes all around.

we are both using the exact same computer build and OS(windows 7 ultimate 64bit) as i built both computers.

anyway this is mostly for curiosity and i am just going to drive to my brothers house to get the files i need again, but if anyone has any idea whats going on please reply, im keeping both disks for comparisons sake.

thanks for reading,
wildbill

 

[alyoshka]

DVD's usually do not support Multi Session Writes. If you're using a DVD-RW to write you files on, then it's ok to write them and then reformat it and write again on the same disc. But using a DVD-R isn't going to support re-writing. And will not support new sessions.
After one write the disc closes the session and you can read what it written to the disc. On the other hand leaving a session open and then writing to it again later erases the TOC making it blank or just data from the second session and closing the disc.

 

[wildybill]

ok yea because the primary session was never closed, he just transfered a bunch of folders, and then because 1 of them wouldnt fit he had to manually transfer half of the contents of 1 of the folders.

well i guess its simpler then i thought, i already thought that those type of disks couldnt be used for re-writing and such but then i wonder, why the hell windows let him do it in the first place if its impossible?
then again... "Nothing's Impossible" right?

 

[alyoshka]

If I wanted to literally show that it was possible, I'd use a marker on the DVD....

 

[wildybill]

Best answer selected by wildybill.

 

[Mousemonkey]

This topic has been closed by Mousemonkey