Does anyone know how to open up an old file from a .taxform with out having the program or needing to repurchase the program?

if the file name ends with .taxxxxx you need the app for that year or you can send it to an outside service to print out the return. if it ends with .pdf you need an app that can read that type of file. Adobe Reader is one but there are others. if it ends with something else you'll have to search the web for an app that can read it

If you have old .tax files (like .tax2021, .tax2020 etc.) you can try converting them to pdf files at  Www.Taxprinter.Com 

It might be expensive.  They are not connected with Turbo Tax.  Use it at your own risk.