Did you just run into a file that has been digitally signed by PC Tools Labs? If that's the case, please read on.
You'll typically notice PC Tools Labs when running the file. The publisher name is then displayed as the "Verified publisher" in the UAC dialog as the screenshot shows:

You can view additional details from the PC Tools Labs certificate with the following procedure:
Here's a screengrab of a file digitally signed by PC Tools Labs:

As you can see in the screencap above, Windows states that "This digital signature is OK". This means that the file has been published by PC Tools Labs 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 see the address for PC Tools Labs, such as the street name, city and country.
VeriSign Class 3 Code Signing 2004 CA has issued the PC Tools Labs certificates. You can also view the details of the issuer by clicking the View Certificate button shown in the screenshot above.
The following are the PC Tools Labs files I have collected, thanks to the FreeFixer users.
The FreeFixer tool treats files from PC Tools Labs as trusted, which means that the PC Tools Labs files will appear with a green background and that there's no removal checkbox for the file. However, as you can see in the scan results below, a few of the anti-virus scanners detects the PC Tools Labs file(s). My guess is that those detections are incorrect and that the files are safe. It is unlikely that PC Tools Labs would ship a malware file.
| Detection Ratio | File Name |
|---|---|
| 0/49 | pctgntdi.sys |
| 0/50 | pctappevent.sys |
| 0/41 | dsservice.exe |
The detection percentage is based on that I've gathered 140 scan results for the PC Tools Labs files. 0 of these scan results 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 done on certificates with the following serial numbers: