Did you just find a file that has been digitally signed by TaxACT Inc.? If that's the case, please read on.
You will typically notice TaxACT Inc. when clicking to run the file. The publisher name is displayed as the "Verified publisher" in the UAC dialog as the screenshot shows:

You can view additional details from the TaxACT Inc. certificate with the following procedure:
Here's a screengrab of a file signed by TaxACT Inc.:

As you can see in the screenshot above, Windows reports that "This digital signature is OK". This means that the file has been published by TaxACT Inc. and that no one has tampered with the file.
If you click the View Certificate button shown in the screencap above, you can examine all the details of the certificate, such as when it was issued, who issued the certificate, how long it is valid, and so on. You can also examine the address for TaxACT Inc., such as the street name, city and country.
VeriSign Class 3 Code Signing 2010 CA has issued the TaxACT Inc. certificates. You can also view the details of the issuer by clicking the View Certificate button shown in the screencap above.
The following are the TaxACT Inc. files I have collected, thanks to the FreeFixer users.
| Detection Ratio | File Name |
|---|---|
| 0/56 | UpdateMgr.exe |
The detection percentage is based on the fact that I have gathered 56 scan reports for the TaxACT Inc. files. 0 of these scan reports came up with some sort of detection. If you like, you can view the full details of the scan results by examining the files listed above.
The analysis has been done on certificates with the following serial numbers: