dtapart files that I can't open

I have two folders that have turned into dtapart files.
I don't know of any thing that I did to make this happen.
Is there any way to change them back or open the files.
I have tried to use VLC player  but they won't open.
This is what the file turned into. When I downloaded it it only had the info to the avi
I have tried to erase the numbers but they still won't open.
I may have downloaded some of those files with "Down Load Them All" but not all of the changed files

ShaniaTwain-ImGonnaGetchaGood.avi--(61078884-4090-92eb-6550caf11fb8).dtapart

Thanks for any help

It looks like a partial download, using "Down Load Them All".
If it's partial download, it won't open.

Its not a partial download, I have folder with hundreds of files that I have viewed many times. I do not know why this folder changed, other folders within this folder did not switch to dtapart files.

Thanks for your reply

you mean you've viewed this file before? is that the only file that changed?

All of the hundreds of clips have been viewed before, avi, wmv, zip formats. They all switched to dtapart files and I can't veiw them anymore.

Did you try to rename any of files, you know for sure, you played them before?

Go through what rename them means.
I have changed the file by eliminating the numbers and adding avi or wmv and Windows says do you want to rename I say Yes. Is this correct and what you mean? They still wont open.

It looks like a partial download, using "Down Load Them All".

Actually, the name is DownThemAll. 

Do have it installed?  If so, I think I'd remove it and see whether that solves the problem.