System: MSI BX Master 6163 mb; PII 400 w/256MB; 20GB (master on ATA66); ATI Rage Pro 3D, SB Live, DVD & CDRW ROM drives. Win98 SE Problem: frequent system lockups even with no PC activity/usage; also while using IE5 (and later 5.5), IPFs referencing at times GDI32, MSHTML and others; or just browser shutdowns! I'd recently replaced replaced original IDE drive with the 20GB. Lacking m/b's OEM CDROM I did not have the UDMA/66 drivers (PDC 20262 controller), so windoze reported "ms-dos compatibility-mode paging". Corrected this with proper drivers but above-mentioned proplems still exists. Have reinstalled system from scratch 3xs so far. Any ideas? TIA Ian Carmichael NYC PCSOFT's List Owner's: Bob Wright<[log in to unmask]> Drew Dunn<[log in to unmask]>