Format with the file extension of the file to open the .xls inconsistencies how to do?

　　Some time ago I was watching the news about excel, xls notice formatting problems, such as file format suggesting "you try to open the file extension xxx.xls inconsistent format name specified when opening the file. Verify that the file does not open the file before damaged and from a trusted source. whether to open the file now? ", uninstall reinstall Office 2007 does not work. This is what causes it? In fact, because the warning message Excel 2010/2007 are added to a user notification function. A warning message can help prevent unexpected problems due to the actual content of the file and the file name extension may not be compatible and may occur.
　　When anyone using Excel knows the two most common Excel file format is xls format and xlsx format, estimated that many people can not tell what is the difference between the two, do not know to save a new Excel file, whether the election which format.
　　This small article is not intended to go from theory to distinguish between the two formats, only the choice of different file formats, have any effect on our actual use.
　　The only reason to use xls can only take care of the old version of the software compatibility required
　　only in one case, we should use the xls format, that is to take care of the old version of the software compatibility needs. The old version of the software refers Excel2003 and previous versions of Excel, and other old business systems (for cost considerations, many business systems or N years ago that set).
　　If there are no compatibility concerns, then, must not save an Excel file with xls format.
　　That Specifically, what harm using the xls format it? The following list them.
　　If your data exceeds 65536 rows and 256 columns, using xls cause data to be truncated
　　as shown below:
　　general form is difficult to exceed 256 (if exceeded, may need to be considered under the table design is reasonable), but beyond the line on 65536 very easy, especially corporate data. When we save a file in xls format, data other than 256 and 65536 rows will be lost. How high the severity of data loss, no need to say.
　　After using xls format, Excel can not use a series of new features
　　as shown below, add-ons fails, three-dimensional map is not available, the mini-map, and filters are often inaccessible. There should be other features will also fail together (do not know if I have a master list xls format causes all function failure?)
　　Using the xls file format will cause the volume surge
　　As shown below, the same file, using the save xls format and use xlsx save format, the minimum difference in volume is 2 times as much, with a maximum 10 times, the larger the file size, the greater the difference in volume different file formats.
　　Some would say that now the hard worthless, wasteful xls format this space is not worth mentioning.
　　However, the problem of large file size brings more than just the cost of storage, and transport costs: Our files are always to be sent to different people to see that you are willing to receive a file 1M lack of it, or would like to receive a close 8M file? If you send e-mail, and some e-mail providers limit the attachment altogether no more than 2M. Some people like to see the document using a mobile phone, although the flow enough, but transfer large files takes more time, is not it?
　　Use xls file format irreparable mistake
　　Although Microsoft Excel has been very reliable, but sometimes inevitably encounter an error in the case file. If xls format, the file once damaged, it is difficult to save the contents therein. And if xlsx format, not only to reduce the possibility of mistakes a lot, even once the error, you can also save a part of the file contents.
　　For example, the following file, although damaged, but open xlsx file with winrar, we can retrieve the file contents (but requires additional processing steps show question):
　　Finally, xls xlsx format not quick format
　　This is my personal experience, it is difficult a chart or data to support. However, the actual use, we found the same file format and open the xls xlsx format, open a significant difference in speed. Speed I used more of PowerQuery, and sometimes can not handle the xls file format or slow processing unbearable.
　　Conclusion
　　So, if there is no compatibility reasons not to use the xls format, but rather use the xlsx format to save an Excel file.
　　Hopefully this short article will help to needy junior partner. Finally, I personally recommend suitable experience last nuts cloud corporate network disk , it is strongly recommended to everyone.