Why would I have 2 system files in the Chest

[Texas-Hansen]

Using Avast Pro.  I noticed today when looking at the Chest in Avast under subpart "System files" I have two system files that were transferred there on the date when I first installed Avast Pro.  The two files are:

Kernel32.dll   (orginal location C:\Windows\system32)
wsock32.dll   (orginal location C:\Windows\system32)

It does not list anything under the Virus column or Comment column and these are only located in this subfolder of the Chest.  Is this normal?  If not, how do I proceed?

Thanks

EDIT:  I'm guessing this might be normal as I took a look at my wife's XP laptop running Avast Pro and it also has the system files in the "System files" subfolder of the chest but has a total of 3 system files instead of my two.  Perhaps that's related to Vista 64 bit, which is what I'm running on my system. 

[oldman]

The reason there is only 2 files may very well be vista related. The files on both computers belong there. They are backup copies placed there by avast. So you guessed correctly.

[Lisandro]

I have Vista and three files
Just to mention these files are clean and stored there for backup purposes (although I may admit I never saw avast asking for restoring them, neither avast is able to do it at boot time  ).

[Marc57]

I have the same three Tech, Maybe Texas-Hansen only having two has to do with Vista 64 bit, But I'm not sure.