CSV (comma delimited) files are supporting a very large number of rows. Many than Excel 2007 can open. But CSV files has some limitations in order to manipulate and edit data. Often you need to work directly in Excel.
If you have a big CSV file with millions of rows, Excel 2007 will open that file but only until 1.000.000 row. the rest of the .csv file is not loaded. So, in order to use all data, split the CSV file in multiple ones and after that open them with a software.
1. We will use a free software
There is a small software that will allow you to make it. Grab it from this page and save it on your hard disk. Open archive and copy the files on your hard drive. This tool does not requires any installation, just run the executable file.
2. Double click the .exe file and browse for .csv file which you will need to split