I did find a reference in Known Bugs to a source file size limitation when importing, but it's 4 GB, not 1. I think you need to try this on a drive with more capacity, a flashdrive is all you need for this, and see what happens then.
For More Information see: Import of a large CSV file halts after 4GB
This is one of many acknowledged bugs that can be found in the Known Bug List here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: http://www.4shared.com/file/8orL8apk/FMP_Bugs.html
Another thing I forgot to mention was that FileMaker Pro Advanced is installed on the C: drive but the FileMaker file and imported file are on a separate drive. The C: drive is the drive that has less and less free space as the import runs. After the import is done the C: drive has most if not all of the hard drive space back. Seems like there is some kind of temporary storage going on during the import.
The import works fine when run on a Mac with plenty of hard drive space. Just wanted to be sure this couldn't be some kind of problem with running the import on Windows and that more hard drive space will fix it. Thanks for your help.