Files with the .7Z extension contain archived data, which can be compressed and encrypted. It enables to use pre-processing algorithms - BCJ, BCJ2 and Delta Encoding. An archive can be divided, and in such situation extensions of specific elements of a package are complex: name.7z.001, name.7z.
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 NTFS file after converting to 7Z may differ slightly from the original. The most important information should be kept, but if you want the file after conversion from NTFS to 7Z 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 NTFS to 7Z does not meet your expectations, you can simply try to find on the Internet a different version of your file in NTFS format, properly converted to a 7Z file by someone else. If this fails, use the information provided in the further part of the website.
Unfortunately, if after performing the two previously described steps (trying to find your NTFS file converted by someone else, and the attempt to convert it to 7Z 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 NTFS file in its original format (without conversion to 7Z file). Such a solution will be difficult to implement, but it certainly will give the best result.