How is Ubuntu accessing the c:\ drive? Or do you mean that its the original copying of the data from c:\ (presumably within Windows) when it stops copying?

Where are you copying from and to? A shared partition/folder? An external drive? Would a copy yo a local file be more successfully?

Do you run this account with complete download of messages, or headers only? I'm wondering if the download effort is necessary or even useful; in general you'd expect the POP account's folders to hold complete copies of the messages.

Well, I haven't shared the C drive from the old Windows computer, but did share my home folder on the new computer. So from the old Windows I drag and drop from C:\Documents and Settings\Edward\Application Data\Thunderbird\Profiles\xxx.default\ to \\192.168...\lhome\.thunderbird\xxx.default\. As I'm doing that, the file Inbox stops at 62% with an error. Everything else gets copied over without problems.

I later try to copy this Inbox file within the same computer (eg C to E) and it still stops at 62%. Knowing some programming I try to copy one byte at a time and it stops at 62%, this time presenting the Windows Error Code 0x17.

Thing is with Gmail is that I believe Thunderbird does download the latest emails from Gmail, meaning that it holds some sort of checksum on the whole inbox so I don't get the whole thing, and whatever I delete in Thunderbird doesn't get deleted from Gmail. There are some messages I do move to the Local Main, but some that I feel are important I keep in the Gmail Inbox.

I copy everything, with the exception of ".default\Mail\pop.gmail.com\Inbox" because when it got to 62% of 485MB, it says "Error: Cannot read C:\...\Inbox".

That folder will have 2 files. inbox and inbox.MSF.

The MSF file is an index into the other which actually contains your mail. The MSF conains just enough information to fill the lists of mail in Thunderbird. It saves making accesses to the main store and slowing the user interface. Looks to me like you best look to fixing the issues with the main MBOX file that goes bad at 62%

I suggest you run some file diagnostics over your old hard drive. It clearly has issues. Before hand, you might try using the import export tool to export from your old windows installation in EML format. That might recover things that will be lost when the disk repair occurs.

https://addons.mozilla.org/en-US/thunderbird/addon/importexporttools/

Well, something happened... With the Export / Import, I got the saved mail onto the new computer. Except it is now 14MB, but all that I had saved is there.

Thanks.