Rajesh actually meant with O/S version the actual Windows version - e.g. Windows 2003 32-bit. The snapshot method to be used depends on the O/S version. Before NBU 7 the default was VSP. With NBU 7 the default is VSS (See Admin Guide I).
I would speak to system owners - seems someone might have deleted 'E:\DRIB\
file-Full Database Backup 20100202' while the backup was in progress:
failure reading file: E:\DRIB\
file-Full Database Backup 20100202 (WIN32 2:
The system cannot find the file specified.)
Snapshot Error while reading file: GLOBALROOT\Device\HarddiskVolumeShadowCopy15\DRIB\
file-Full Database Backup 20100202
Snapshop errors have been around for as long as Windows Open Files have been around and for as long there have been attempts to back them up via snapshots.
Check Host Properties -> Master -> Client Attributes -> add client name
Check that VSS is selected. You might want to select option to 'disable snapshot and continue'