Since there is no authorized source for 2010 TurboTax software, any copy that you buy now might be worse than a beta version. It could contain viruses, spyware, or other malware.
As fanfare said, if your .tax2010 file contains a state tax return, you will not be able to open it in TurboTax unless the state software is installed. But the state software for 2010 is not available, even from Amazon or eBay. So your only hope is a service such as the one discussed in the thread that Mike9241 referenced.
In the future, always save your tax return as a PDF in addition to saving the TurboTax data file, so you will have a copy that you can view or print. For tax returns more than 7 years old, your own records are the only source.
