Reboot into Safe Mode: please see here if you are not sure how to do this.
Open Hijackthis and do a scan. Place a check against each of the following, making sure you get them all and not any others by mistake:
O4 - HKLM\..\Run: [yahooex32] C:\WINDOWS\yahooex32.exe
O4 - HKLM\..\Run: [inetreg] C:\WINDOWS\inetreg.exe
O4 - HKLM\..\Run: [p2pnetworking] p2pnetworking.exe
O4 - HKLM\..\RunServices: [p2pnetworking] p2pnetworking.exe
make sure all other windows and programs are closed
Click on Fix Checked when finished and exit HijackThis.
Using Windows Explorer, locate the following files/folders, and delete them if found:
p2pnetworking.exe do a search and delete all instances of this file
Now run CleanUp!. Click CleanUp and allow it to delete all the temporary files.Reboot your computer into normal windows.
Please run an on-line virus scan at Kaspersky OnLine Scan or if that doesnt work, you can use TrendMicro or BitDefender. (Please post the results of the scan(s) in your next reply)
After all that, please post back with how things went as well as the logs requested and a new HiJackThis log.
have you installed a Packet Sniffer on purpose on your system and uninstalled it?
this indicates this observation and if you don't want it there then we need to fix it also
O23 - Service: Remote Packet Capture Protocol v.0 (experimental) (rpcapd) - Unknown owner - %ProgramFiles%\WinPcap\rpcapd.exe" -d -f "%ProgramFiles%\WinPcap\rpcapd.ini (file missing)