Window asked me to reactivate my window xp , after a norton scan i just installed

hi, i dont know whats wrong here. so i need help.

today i installed a new license of norton internet security as my old is expiring. 

i successfully installed norton internet security as usual in the past.

i did a quick scan and a reputation scan and for both times, the software requires me to reboot saying it needs to reboot to clear something.

so i rebooted but came a message saying something about my hardware changes and window changes hence need to reactivate my window. and an option of saying yes or no.

the 1st time i say yes n i ended up a dead screen with no icon task bar or anything on my desktop.

the 2nd time i try no and i was able to boot into the desktop. i thought everything was ok and i thought the problem was due to reputation scan and it was solved. so i run a quick scan

and the same thing happen. --> system asking me to reactivate my window. (if i click yes)

what is the problem here ? i suspect its due to scanning and clearing of virus . in this case, i would not be able to scan since, after scanning , the same problem will happen when it tries

to clean some virus or whatever. without able to scan and cleaning, hence my internet security becomes useless.

i checked with the store where i purchased and he said the window was corrupted and need to reinstall the window. i not sure about this cause i havent try out.

if this problem can be solve without reinstalling my window. it would be great.

it would be doublely great if i still can use my norton without occuring this problem.

pls help ...

 

thanks and regards

(aka . i was lucky in the sense that i have a backup disk with me. hence i was able to recover my window else all is lost. in this case , the lost was minimal but better than losing the

whole window system o/s )