System is slowing down noticeably around 15 mins after boot-up. I have used System Mechanic but this has not resolved. I have used windows utilities but no luck. Upon rebooting the system works fine again for similar time period before slows down. System is Duron 700,128meg ram, fic az11e mthboard, ibm 75GXP 30mg harddrive,win 98. Also having occasional problem whereby incoming phone call to house causes computer to crash (generally while playing games). Any help would be appreciated.