電腦不能成功進入window

Hi 請各位高手指點迷津,

我的電腦正在以下程況中，突然彈出以下方塊，及後重新開機亦如是，不能成功進入window。
- Northon Antivirus 正在更新
- FreeRam XP Pro 運作中
- SUPER AntiSpyware 正在更新


Microsoft Visual C++ Runtime Library
Buffer overrun detected!
Program:\??\C:\windows\system32\winlogon.exe

A buffer overrun has been detected which has corrupted the program's internal state. The program cannot safety continue execution & must now be terminated.



Processor
2.00 gigahertz Intel Celeron
8 kilobyte primary memory cache
128 kilobyte secondary memory cache
Main Circuit Board
Board: ASUSTeK Computer INC. P4V533-MX Rev 1.xx
Bus Clock: 100 megahertz
BIOS: American Megatrends Inc. 1005.001 09/19/2003
Memory Modules
496 Megabytes Installed Memory
Slot 'DIMM0' is Empty
Slot 'DIMM1' has 512 MB
Drives
WDC WD800JB-00ETA0 [Hard drive] (80.03 GB) -- drive 0, s/n WD-WCAHL3598363, rev 77.07W77