Yes, in this case you can use 7-Zip to extract files from the MSI package. However, 7-Zip is not "fully equipped" to handle MSI packages like lessMSI. I hope that Igor Pavlov, the developer of 7-Zip, will add better functionality to read the contents of MSI packages properly.
There Is A Huge Difference Between Backing-Up Your Local Machine, And Backing-Up Your Remote Machine.