Nassra,
This can happen when the chipset used has a parallel port but is not implemented (fully) on the motherboard. The parallel port is not completely turned off in the BIOS. It may not appear in the BIOS setup screen but the code in the BIOS has the parallel port (mostly) there. PC-Doctor sees this, enumerates it and when it tries to test it fails because it is nonfunctional.
The only fix for this is a BIOS update with all the LPT port registers turned off. Please contact the BIOS vendor for this.
In the interim simply do not run the test on this system as the failure can be safely ignored because there is no external parallel port.
-Fred