How to unrar from multiple archives.
1. Find the folder with the multiple archives in it.
Open the folder.
2. Inside the folder you will see multiple rars.
In this case there are 26 rar files.
3. Open the FIRST rar file.
Inside you will see the item that you want to extact.
4. Simply click and drag the file from the Winrar window, to your point of extraction.
Winrar will start extracting it.
5. The file should sucessfully extact and your done. If not refer to troubleshooting.
When you get this error when try to extact the file.
It means that it cannot find the part that it is looking for. Take note of the archive it is asking you for.
In this example it is missing part 26. This could mean that part 26 is either not there, or is corrupt. Too fix this problem, make sure that part 26 is in the folder, and if it is - redownload it as it may be corrupted.
When you get this error message when try to extract.
As it states all/some/few of your archives may be corrupted. Try Re downloading them.
Other important points
There's also the other WinRAR naming convention, with .rar, .r01, .r02, etc. In that case, open the file with the .rar extension, which is usually the last one.