pdb是什么文件，要签名----》

我用softice 装载sys, 但是总不成功，出现了
D:\WINNT\system32\drivers\packet.sys opened successfully
Translating D:\WINNT\system32\drivers\packet.sys. . .
Error: PDB file f:\ntddk\src\network\ndis\packet\driver\objchk\i386\packet.pdb has wrong signature
Translating D:\WINNT\system32\drivers\packet.sys. . .
Error: PDB file f:\ntddk\src\network\ndis\packet\driver\objchk\i386\packet.pdb has wrong signature



怎么解决好