Files take longer to open in Excel 2000 and later versions than Excel for Windows 95 Files

When you open a workbook in Microsoft Excel, the file may open much more slowly than it did in an earlier version of Excel (for example, in Microsoft Excel for Windows 95). Additionally, although you may have several workbooks that are roughly the same size, some may open much more slowly than others.

When you open a workbook in Excel, the file is scanned for macros.

When you open an Excel file, the file is scanned for macros regardless of the location of the file (either a local file or a file that is on a network share). In Excel, when you open a workbook on a network share and the workbook is scanned for macros, the workbook data stream can be scanned for macros. Depending on the elements in the workbook, it may not be necessary to read the whole Excel file into memory.