restore the computer to its previous date so that all the settings back.
if needed download the Nero burn software from the internet and try to write the DVD.
try another DVD to write so the insert new DVD problem will be removed.
may be your computer is infected by the viruses so update the installed anti virus software and scan the computer with this anti virus software.
for further assistance you can approach at this source at
http://www.iyogi.co.uk/install-antispyware.htm l