1. Please re-open HiJackThis and choose do a system scan only. Check the boxes next to ONLY the entries listed below(if present):
O4 - HKLM\..\Run: [vptray] C:\Program Files\NavNT\vptray.exe
2. Now close all windows other than HiJackThis, including browsers, so that nothing other than HijackThis is open, then click Fix Checked. A box will pop up asking you if you wish to fix the selected items. Please choose YES. Once it has fixed them, please exit/close HijackThis.
Reboot and tell me if the problem remains