Installing Backup Exec and Backup Exec System Recovery on Same Server.

Hi,

We have a Exchange server where we Installed Backup Exec and Backup Exec System Recovery on the same. We are getting this error frequently . Any idea is appreciated One concern can we install Backup exec and Backup exec system recovery on same server. Backup exec job is failure and BESR is success.The Symatec Backup exec error is

 Snapshot Technology: Initialization failure on: "Microsoft Information Store". Snapshot technology used: Microsoft Volume Shadow Copy Service (VSS).
 VSS Snapshot error. A Microsoft Volume Shadow Copy Service (VSS) snapshot is already running on the target computer. Only one snapshot can run at a time.  Try running the job later

And in the windows event viewer I get

An attempt to open the file " for read only access failed with system error The process cannot access the file because it is being used by another processThe open file operation will fail with error -1032

Thanks.