.net framework issue

i am running windows7 64bit build 7232. i have never had any problems until now. whenever i boot up, i get this :


http://i725.photobucket.com/albums/ww255/osmington/711.png

i cannot install this anyway as its just for 32bit versions ?

any ideas please guys.

 

http://www.microsoft.com/downloads/...ED-04EB-471E-8A99-3C61D19A4C5A&displaylang=en

 

i have d/l the update, the message i am now getting is 'you must go to turn windows features on or off before you install this'
i can go there, but which feature do i either turn on or off ?

thanks

 

problem sorted. i removed my lexmark printer from startup and all is fine now. so i guess there's an issue with lexmark and windows 7.