Hi,
It seems to me that this is not a VM running on the host but a vib (vSphere installation bundle) which explain why it disappeared when you installed ESXi 5.5
The way to install it is by connecting to the host via SSH and run a command such as:
esxcli software vib install –v /vmfs/volumes/datastore2/../../Dell_bootbank_OpenManage.vib
Please make sure to write the full path to .vib file
Also please note that the version that you have there left from old installation might not be compatible with this version of ESXi you upgraded to
In that case you will have to download another compatible version of this bundle
Best regards,
Chen