File too big

Autocad 2010 C3D. I have been trying to copy a file and place it in another but when I hit the copy command the hourglass comes on then nothing. I go to the Task Manager window and it says AutoCad is not responding. I have tried to copy a small portion and it works ok but I was wondering if anyone else has run into this before. The original drawing came from a DGN but I haven't had problems with this in the past. They just haven't been this large.

How large is it, and was it created in PROSTEEL?

I knew as soon as I hit the post button that I should have included the size (60 mg) It was created in ARCGIS (formerly arcview) And I don't know if it makes a difference but the file, which doesn't seem too unwieldy to me, is made up of polylines.

ARCGIS can export to .dxf and to .dwg, can't it? Those file formats may be less painful. 60Mg of polylines IS kinda huge. Have you tried '-purge' and 'audit' on the file to dump unnecessaries?

It was exported as a dwg. I ran audit and the only thing it fixed were a few lettering mistakes. I was not sure what you wanted me to purge. I am thinking that maybe it is just too large to handle at once. Thanks for the suggestions.

If you're using Civil3D then use the MAP dwgcleanup tools, mapclean command, or at least the vanilla command Overkill.

Try click print screen in your key board

@Logiseek: I'm really not sure how is going to decrease the size of OP's file?!?

I would like to thank everyone for your suggestions. I tried most but time constraints forced me to move on. I copied the file to a thumbdrive and then downloaded from that to the new file. Again, thanks for your time.

D