The AVG virus vault on my PC shows these 2 virus.

Trojan horse.Dropper.Gerneric.HRO C:\Documents....... \rtf..exe

Win32/Dupator C: Windows\Kernell32.dll

There is an Heal option is not active. I am wondering what will happen if I press Wipe Objects.
Is there any chance windows can become unstable if Kernel32.dll file is removed?

As it is not affecting anything, should I leave these files in the virus vault?

I seriously wouldn't try to clean or 'wipe' the kernell dll file.
After some searching i found this 'The virus is unable to run on Windows NT and 2000.'

So the Win32/Dupator can't actually start up on windows nt/2000 which includes xp and vista (I think..)

Anyways, if you are on one of those OS'es you SHOULD be safe but there is a very high chance you have a load of other viruses.
You can try a boot into safe mode (F8 if i remember correctly on boot screen) then run your antivirus and let it scan/clean. Also the fail safe option would be to reformat, though you'd need to reinstall everything and make sure you have backups of data prior to reformatting.
Hope it helps!

-HellFire

Most likely it's not a file crucial to running windows. If the virus vault doesn't give you the option to heal the file, it's pretty much certain it's a "pure" virus, and not an infected system file. Also if it's in the virus vault it's being restricted from interacting with the system, so if it were to be a needed file your system should already not be starting up. I would go ahead and delete it, and if for some reason it won't start after that, then you can simply repair the installation. though if that were to occur i would move my important stuff off the c drive, assuming that's your partition windows is installed on, and reformatting the partition. it can be less hassle alot of the time to reinstall rather than repair, especially if the virus has a high sophistication level and getting rid of it means you'll have a limping system recovering from the effects. Also be sure to disable system restore, and then rebooting in safe mode and running a complete virus scan. Otherwise you delete the virus, but the next time you restart the computer, it just reinstalls itself from the restore files.