My specs: win 7, i7 1.6ghz, 4gb ram.

I have used freeze on all tracks. There are 9 tracks and the song is about 4 mins. I switched off wireless and virus & firewall. I changed buffer to 200 for bounce. The current mixing down audio is taking about 1.5 hours. This is obviously very slow. What can I do to rectify problem? I closed various services too. Thanks.

Not sure what would causes that, but the obvious immediate solution would be to do a real-time bounce (uncheck Fast Bounce in the export options). At least you'll be down to 4 minutes that way.
 
When did you start having trouble. Is it just this project? Probably some plugin causing trouble, unless you froze FX with the tracks...?

Is it possible the project is exporting more than a 4 minute selection? Was a time range specified for the export?

OK it was the time range (13mins).  I had omitted to notice an accidental node in an automation lane.  It showed in one of the track lengths after I had freezed it.   Thank you.
 
 

Casestudy26
OK it was the time range (13mins).  I had omitted to notice an accidental node in an automation lane.  It showed in one of the track lengths after I had freezed it.   Thank you.
 
 

I hate it when that happens!
-DG

Hmmm... okay. Good catch, Steve. But why the radical increase in processing time for a 13-minute selection?
 
 

I would have expected the selection to be much longer but without seeing the project it is hard to suggest an explanation. The original guess was a shot in the dark.