Spyware?malware?VIRUS? cant do anything

hello, i have windows xp pro service pack 2,

and its potentially infected with virus or spyware or malware i dont know.

it wont let me do anything, task manager has been disabled, aswell as other features, my backcround changed,

the log off button and start menu have been modify. (no log off)

i cant run any programs, like hihackthis, combofix, spybot, i double click but it wont do anything. i even went in safe mode, and the same thing is happening, alot of pop ups are showing, with those system alert windows, and system tray icons.. i have a lot of important information that dont want to erase, so i want to avoid the re formatting step.

thank you

 

i followed the steps =)
i think it fixed everything, i dont receive any pop ups, the wallpaper was fixed, the start menu was fixed. and task manager is now enabled. but there is one problem.. it doesnt show right. look at the image attatched. How can i fix this

it doesnt show the FILE, EDIT etc.. also the Tabs, programs processes.. it doesnt show that..

thanks in adnvanced.