I have been using a desktop computer which is installed with windows XP. From past 2-3 days i am not able to download any PDF files. whenever i try to do this my browser crashes can anyone tell me what is going do i need some download manager or so please guide me....
Which OS? Which browser? Have you made any software changes recently? Can you read the pdf without downloading?
Ditto on Whappo's post.
My guess based on your information above is your AV,Amalware, or firewall has added a block , Maybe from an update. So try to update all of these again & see if the problem goes away. If not then check each one.