Here are the parameter's effect: /OVI=<number> Overlapped I/O. Controls the multi-threading used by this version. This switch is only used when restoring an image. 0 - no multi-threading. 1 - Overlap PQI reading and decompression with Disk writes (2 threads) 2 - Overlap PQI reading with decompression (2 threads) 3 - Overlap PQI Reading with decompression and with Disk writes (3 threads) 4 - Same as 0 5 - Same as 1 6 - Same as 2 but with PQI read-ahead 7 - Same as 3 but with PQI read-ahead The default value is 3. Setting this value optimally can significantly improve performance. When the PQI is on the same disk as the partition that is being restored, the optimal value will probably be either 2 or 6. In most other cases, the optimal value will be 3 or 7, unless the partition data is highly fragmented. /PRI=<number> Set process priority. Accepts values 1-6. 1 - Idle priority 2 - Below normal priority (New to XP - not yet supported) 3 - Normal priority 4 - Above normal priority (New to XP - not yet supported) 5 - High priority 6 - Real-time priority The default value is 3. If no other processes are running on the machine at the same time as PQIDeploy, this switch has very little effect. However, when other processes are running, such as system diagnostics, you can use it to control whether PQIDeploy runs at a higher or lower priority than those other processes.