what’s wrong with my computer?i had been install NOD32, it always prompts a virus when i Download something.

Hello friends , some virus can not be  kill  in the normal mode .
Antivirus software sometimes  errors reported , mainly because of some special software program  need to call the system file.
I personally think it is best to replace the anti-virus software.

I suggest that you spend money to buy Kaspersky , I use Kaspersky , Kaspersky is a thirty-day trial period , you should first uninstall NOD , try Kaspersky .If the the Kaspersky test results like NOD, the file You download does contain the virus , then you exchange NOD back.

the file You download should contain malicious code or virus , NOD32   is also sensitive on some malicious plug.

the crack file inside Some software  also be seen as virus .

x97m/mailcab.a worm is a macro virus in excel file , so when you open the excel file try not enabled macro