hi, i am a new comer. plaese help me to mix the following problem that drives me crazy. after a new harddisk has been installed, my computer keeps on restarting suddenly, without warning. and i cannot do system scan. :hotbounce there are error repost: bc code:9C BCP1: 0000 0000 Bcp2: 8054d370 bcp3: c411c000 BCP 4: 0000 0136 OSCer: 5_1_2600 SP:2_0 prouct: 256_1 technical report：c:\docume~1\tsw\locals~1\temp\werca29.dir00\mini013106_4.dmp c:\docume~1\tsw\locals~1\temp\werca29.dir00\sysdata.xml i have observed that the codes has change for serval times, eg., bc code:9C BCP1: 0000 0000 Bcp2: 8054d370 bcp3: f6002000 bcp4: 0000017a and bc code:9C BCP1: 0000 0000 Bcp2: 8054d370 bcp3: 94004000 bcp4: 00000152 since there are many patterns, please forgive me to attach a bit large number of minidump here. looking forward for your reply. V. THX.