Download HijackThis from here & unzip it into it's own, permanent folder, (Not a temporary folder or the desktop & not directly on your hard drive).
If you have anything disabled in MsConfig, please re-enable it/them.
Start HJT & with all browser windows closed, press the scan button. When the scan is finished the scan button will change to save. Save the log to a text file, copy the entire contents of the text file & paste it into the body of your post. DO NOT FIX ANYTHING YET. Most of what is there is necessary for the running of your system.