The restarts are needed to remove the orphan blocks that are currently in memory, hardcoded to 99 in earlier versions of bitcoin if i remember correctly. To avoid this, try
maxorphanblocks=
in clam.conf
We're talking about importing from a bootstrap.dat file. Bootstrap files don't contain orphans, and no network connections are made until the bootstrap.dat import finishes.
Right, but the use of this config makes the process of syncing a lot faster without the need for a bootstrap as he is only 18 weeks behind. Maybe in the new version this problem with the bootstrap file is corrected, but until there they need to sync as fast as possible.
Talking about bootstrap, what version of windows did you try? I think windows limits memory usage for each process to 2gb in the 32 bits version, maybe this have any correlation
https://en.wikipedia.org/wiki/2_GB_limit