Lightroom Preview folders

[nibbles]

hi i have Lightoom 1.2 (Windows) and it has a catelogue of around 25,000 files. My problem is the preview folders located under \mydocuments\lightoom
\Lightroom Catalog Previews.lrdata
\Lightroom Previews.lrdata

, at the moment they are around 2gb in total and i am running off a laptop with limited HD space.
My main concern though is that these folders contain a lot of small files. So when ever i run a program i.e Anti Virus, other Catelogue programs, Defragger, unless i specify to ignore those folders, (sometimes not possible), then it causes long delays for those programs to have to scan those folders. Is there anyway to prevent their generation or to clean them up after use as there presence seems very inefficient.
Regards
David

[madmanchan]

You can have LR throw away the preview files, but of course that makes using LR rather less enjoyable ...

Which programs are you using that insist on scanning these folders? (i.e., which progs prevent you from manually excluding these folders?)