First of all, if you suspect a virus in your system, if you are unable to run
NAV from the CD without installing it, then use an online antivirus scan such
as Trend Micro or the trial version of the best AV program, NOD32. Then get
and run the free scanner from Webroot. If you are unable to correct the
problems this way and get Windows to boot up properly, it is likely you will
need to do a clean installation from scratch. If you are sure you are not
infected and you can boot Windows, you can continue as follows to get your
NSW 2006 installed:
I use NSW2006 without the anti-virus pgm due to its long history of creating
problems with Windows. So, I suggest you try installing it without
installing the Antivirus. Before doing that you need to clean up any old
antivirus remnants and changes to the Windows registry from prior Symantec
installs.
If any old versions of NSW or NAV are now installed, use the uninstall
program to remove them before installing the new version. Always Reboot the
system after every uninstall to finish the process. That is not enough,
however.
Symantec is reknowned for leaving junk in the Windows registry and they
should be removed. The Symantec site has published programs that will clean
up leftover things and these pgms are available from their knowledge base.
If you can't find them on the website, ask support for them via your prior
contact point. Reboot after cleaning before installing anything.
After you are certain that everything is clean, try to install NSW without
the antivirus. Online you can find many other suitable antivirus products
that do not foul your Windows system. AVG Free is a great product and on the
pay-for side, NOD32 is the absolute best.
Good luck.