Hello and welcome to techspot.
Boot into safe mode. See how HERE.
http://www.bleepingcomputer.com/forums/tutorial61.html
Turn off system restore.(XP/ME only) See how HERE.
http://www.bleepingcomputer.com/forums/tutorial56.html
In Windows Explorer, turn on "Show all files and folders, including hidden and system". See how HERE.
http://www.bleepingcomputer.com/forums/tutorial62.html
Run HJT with no other programmes open. Have HJT fix the following, by placing a tick in the little box next to(if there).
O8 - Extra context menu item: &Define - C:\Program Files\Common Files\Microsoft Shared\Reference 2001\A\ERS_DEF.HTM
O8 - Extra context menu item: Look Up in &Encyclopedia - C:\Program Files\Common Files\Microsoft Shared\Reference 2001\A\ERS_ENC.HTM
O9 - Extra button: Encarta Encyclopedia - {2FDEF853-0759-11D4-A92E-006097DBED37} - C:\Program Files\Common Files\Microsoft Shared\Reference 2001\A\ERS_ENC.HTM
O9 - Extra 'Tools' menuitem: Encarta Encyclopedia - {2FDEF853-0759-11D4-A92E-006097DBED37} - C:\Program Files\Common Files\Microsoft Shared\Reference 2001\A\ERS_ENC.HTM
O9 - Extra button: Define - {5DA9DE80-097A-11D4-A92E-006097DBED37} - C:\Program Files\Common Files\Microsoft Shared\Reference 2001\A\ERS_DEF.HTM
O9 - Extra 'Tools' menuitem: Define - {5DA9DE80-097A-11D4-A92E-006097DBED37} - C:\Program Files\Common Files\Microsoft Shared\Reference 2001\A\ERS_DEF.HTM
Click on the fix checked button.
Close HJT.
Reboot into normal mode and turn system restore back on.
Other than the above, your HJT log is clean.
Regards Howard :wave: :wave: