Hello Auntym.
Sounds as if the program you previously used for unzipping your deisgns was not installed onto your new computer.
I utilize WinZip. There is a free download trial for 45 days and than purchase is required after that.
AnnTheGran offers a software program, Catalog Xpress, which opens, stores, categorizes, changes format and sizing of designs. I do not own as yet but thinking of it.
Joan