Win. 98 SE lock-up

When I first put my new PC on line it worked fine, I had an drive fail in a stripped raid array. I replaced it and reloaded the whole system back to where the HDD faild, after using the system for awhile It started having system lock-up every time ascreen saver came on or after running multiple apps. IE windows, or a combo them for awhile. I noticed that CPU was use was hanging around 75-85% use so I replaced the AMD T-Bird 700 with a AMD T-Bird 1200 changed the memory from 224mgs sdram PC100 to 512mgs sdram PC133 this did not cure the problem. I run down the hardware for you to ponder; MB: asus a7v CPU: AMD T-Bird 1200 MEM.: Kensington 512mg pc133 sdram FANS: AMD CPU fan (came in box w/CPU), 40 cfm pci slot exhaust fan, and a twin 1" HDDbay cooler fan (mounted to cool the raid controlled HDD's) AUDIO: SB Live Value VIDEO: N/Vidia GeForce TNT2 256 w/32mg ddr mem./fan onboard MONITOR: Mits. DiamondPro67txv RAID CARD: Promise ATA100 raid 4x supports 0,1,2 modes HDD'S (2)WD ATA100 30gig in mirror mode CDRW: Plextor 12x10x32 FLOOPY Drives: Mits. 1.44, IOMEGA ZIP 250 internal SCANNER: Visoneer 1200dpi I have uninstalled all non-Win 98 SE scr.svr's. system is in jumper-less mode not overclocked Cpu volt 1.8 MB temp. at 40c. Cpu temp.at 70c. MB Bio's ver. 1004 I have uninstalled all but the important programs uninstalled IE and reinstalled it disabled all PWR. Saving options, when the locks-up CTL-ALT, Del. brings up a window that sometimes says sys. busy or waiting for close dialog. a ctl,alt, del. spaced a little apart will restart windows without the scandisk running (like you see if not shut down correctly) I do not know or have run out of ideas as to how to stop this it causes problem when I am at web site or working in office 2000 thank god for auto recover! any help would be great as I have tried other forums without any help!! :'-)