Tower ECT1250, much slower than I expected

I had a Lenovo Laptop I bought in 2021 and this January thought I upgrade to a more powerful system. So go this Tower ECT1250. Both have 32 GB Memory and lots of SSD disk space. Laptop was i7. But my Excel spreadsheet is still very slow. Anyone have any ideas how to make it faster? Everything (BIOS, Drivers and Windows 11) is up to date.