win2000 pro 開機會出現奇怪畫面 ???

會出現以下畫面 :
Windows is verifying files and folder....
Windows replaced bad clusters in file\ PAGEFILE.SYS
of name(null).
Windows replaced bad clusters in file\ program File\Norton Antivirus\NAVOPTS.BAK

Windows replaced bad clusters in file\WINNT\System32\rsvpsp.dll
. ...........................................................................\vga.drv

..................................................................................\wbcache.fra
............................................................................\msxbde40.dll
.......................................................................\drivers\stream.sys
.
.
.
of name(null).

這是因為我不正常開機所致嗎????還是中毒了???還是另有原因????
以上這些Win2000 check 半小時才完成.........但是還是無法開機....
但最神奇的是過了一天電腦突然開機正常..........

在此謝謝大家的回覆