File with .XLS extension contains spreadsheet document created with Microsoft Excel. XLS is a binary file that uses either MS-XLS BIFF8 or BIFF5 standard. Binary XLS file format was used by Microsoft Excel versions 97 to 2003 and older Excel 5.0/95.
XLSM is a commonly used spreadsheet document created with Excel 2007 or later. XLSM files store data in cells organized in rows and columns. XLSM files can aslo contain spreadsheet macros. XLSM is based on Open XML format and uses ZIP compression, similar to XLSX file.
After converting the file to the new format, you will be able to use other programs to support it. Keep in mind, however, that the XLS file after converting to XLSM may differ slightly from the original. The most important information should be kept, but if you want the file after conversion from XLS to XLSM to be the same, you have to do this carefully and choose the proper application from the list below.
There is no guarantee, of course, that the conversion will come up to all your expectations, but it will certainly help you. If, after all, the effect of converting XLS to XLSM does not meet your expectations, you can simply try to find on the Internet a different version of your file in XLS format, properly converted to a XLSM file by someone else. If this fails, use the information provided in the further part of the website.
If after converting the file XLS the desired result was not achieved, you can try to change the format of XLS file to other than XLSM. On our website you will find more information on the following conversion options
Unfortunately, if after performing the two previously described steps (trying to find your XLS file converted by someone else, and the attempt to convert it to XLSM on your own) you still have a problem with your file, then there are only a few solutions left. You can once again try to find and install an application that can open the XLS file in its original format (without conversion to XLSM file). Such a solution will be difficult to implement, but it certainly will give the best result.