> #rebuild index on windows platform
> proutil name.db -C idxbuild all -T c:\temp -TB 31 -TM 32 -SG 64 -t -B 40000 > c:\idx_rebuild.log

Use the Speed Sort (-TB), Merge Number (-TM), Sort Grouping (-SG) and
Blocks in
Database Buffers (-B) startup parameters to improve index rebuild
performance and (-threadnum) 'n' if u have an enterprise license.

You may want to place the temporary directory on another phisical
drive to impove performance also.