I am using TeXworks 0.4.5 r1280 with MikTeX 2.9 on Windows 7 64-bit. When I add
\usepackage{datetime}
and try to typeset the document, I get a dialog window like this:

I select "Install", confirm UAC request and then get the following error on the console:
! LaTeX Error: File `datetime.sty' not found.
If I try to typeset the document again - the dialog and the error appear again.
Same thing happens when I've tried installing wrapfig and a few other packages at random: cases, comma, dowith, microtype. Other packages have installed fine before. What is wrong with my setup? Please let me know if you need more info about my setup in comments.
I've tried this solution: *.sty file not found. Didn't work.
change. Select another one and check you Internet connection. – Sigur Jan 03 '14 at 15:22make clean(deleting dvi aux bbl files etc.) everything worked. – jozxyqk Jun 19 '15 at 09:49