First of all, you didn't unzip/extract hijackthis.. and it's still in the tempfolder.
So I strongly advise to unzip/extract hijackthis.zip.
Read here how to unzip/extract properly:http://metallica.geekstogo.com/xpcompressedexplanation.html
Create a permanent folder and move hijackthis.exe into it. The reason is because hijackthis creates backups and when it's in your temp-folder it can be accidentally deleted.
How do you make a permanent folder:
Click My Computer, then C:\ and then on Program Files.
In the menu bar, File->New->Folder.
That will create a folder named New Folder, which you can rename to "HJT" or "HijackThis".
Now you have C:\Program Files\HijackThis. Put your HijackThis.exe there.
* Download Combofix
to your desktop.
Follow the prompts.
Don't click on the window while the fix is running, because that will cause your system to hang.
When finished and after reboot (in case it asks to reboot), it should open a log, combofix.txt.
Post this log in your next reply together with a new hijackthislog.