Are you trying to upload copyrighted content?
If there is a watermark, it means that somebody owns the copyright. There is no way to remove a watermark.
Instead of using the Youtube upload in Powerdirector, produce the video to a WMV format (WMV has HD formats).
Then upload using your Youtube Account and Youtube's upload Videos.
Carl312: Windows 10 64-bit 8 GB RAM,AMD Phenom II X4 965 3.4 GHz,ATI Radeon HD 5770 1GB,240GB SSD,two 1TB HDs.