Have Windows 7 x32 (35% full - 160gb hdd system disk with 500gb logical drive) and XP SP3 (60% full - 160gb hdd system disk with 500gb logical drive) both have slow scanning with MBAM(new update)....I used to scan everyday with MBAM(full scan) but when I saw that the scanning is getting longer I do a full scan weekly. I rely on a HitmanPro scan every after using the net now. Just keeping MBAM because of it's detection/removal strengths.