Error opening (Access denied) [4]

During the NOD32 scanning I get these messages in the scanning log:

C:\pagefile.sys - error opening (File locked) [4]
C:\Documents and Settings\NetworkService\NTUSER.DAT - error opening (File locked) [4]
C:\Documents and Settings\User\Local Settings\Application Data\Mozilla\Firefox\Profiles\ix1djxdx.default\Cache\89A0C22Ed01 - error opening (Access denied) [4]
C:\Documents and Settings\--------\Local Settings\Application Data\Microsoft\Windows\UsrClass.dat.LOG - error opening (File locked) [4]
C:\System Volume Information\MountPointManagerRemoteDatabase - error opening (Access denied) [4]
C:\Documents and Settings\---------\Application Data\desktop.ini - error opening (Access denied) [4]
C:\Documents and Settings\--------\Application Data\Microsoft\Office\Recent\d2.LNK - error opening (Access denied) [4]
C:\WINDOWS\system32\CatRoot2\edb.log - error opening (File locked) [4]
D:\System Volume Information\MountPointManagerRemoteDatabase - error opening (Access denied) [4]

At the end of the scanning this is the last log:

Number of scanned files: 45329
Number of threats found: 0
Number of active threats: 0

Notes:

[4] File cannot be opened. It may be in use by another application or operating system.


What all does it mean?

 

Thank you ronjor for the fast reply.

ronjor wrote:

How can I make those files to be accessed?

 

Thank you Ron.

Later

 

That may turn out to be useful to see the below sites:
https://www.wilderssecurity.com/archive/index.php/t-19504.html
http://forums.whirlpool.net.au/forum-replies-archive.cfm/501179.html