Did you just stumble upon a download or a file on your computer that has been digitally signed by NETTALK.COM INC.? If that's the case, please read on.
You'll probably see NETTALK.COM INC. when running the file. The publisher name is displayed as the "Verified publisher" in the UAC dialog as the screenshot shows:

You can view the digital signature details for NETTALK.COM INC. with the following procedure:
Here is a screencap of a file that has been signed by NETTALK.COM INC.:

As you can see in the screenshot above, the Windows OS states that "This digital signature is OK". This implies that the file has been published by NETTALK.COM INC. and that no one has tampered with the file.
If you click the View Certificate button shown in the screenshot above, you can see all the details of the certificate, such as when it was issued, who issued the certificate, how long it is valid, etc. You can also view the address for NETTALK.COM INC., such as the street name, city and country.
VeriSign Class 3 Code Signing 2010 CA has issued the NETTALK.COM INC. certificates. You can also see the details of the issuer by clicking the View Certificate button shown in the screenshot above.
The following are the NETTALK.COM INC. files I've collected, thanks to the FreeFixer users.
| Detection Ratio | File Name |
|---|---|
| 0/46 | nettalkd.sys |
The detection percentage is based on the fact that I've gathered 46 scan results for the NETTALK.COM INC. files. 0 of these scan reports came up with some sort of detection. If you like, you can review the full details of the scan reports by examining the files listed above.
The analysis is based on certificates with the following serial numbers: