bser.exe using up to 99% of CPU

I have a Toshiba 4200 laptop which I have recently upgraded from Windows NT 4.0 Server (SP6) to Windows 2000 Server (SP3).

After upgrading a process called BSER.EXE uses all the available CPU running at between 89 and 99%. I cannot terminate thisprocess by any of the usual means.

A search of the web led me to disable Toshiba’s Advanced Power Management system and Windows NT Utilities before upgrading as Windows 2000 does all this anyway (I had a Norton Ghost backup and restored it to try again). However the problem remains – BSER.EXE is using up to 99% of the CPU.

What purpose does BSER.EXE serve?
Can I disable BSER.EXE by renaming the file so that it won’t run, without upsetting anything else?