As we all know, Windows XP SP2 adds a new security feature - DEP (Date Execution Prevention Data Execution Protection), you can protect your computer from viruses damage. In line with Microsoft's DEP technology, Intel and AMD have developed a corresponding anti-virus CPU.
DEP's anti-virus principle
If your system is upgraded to SP2,
Windows 7 Code/, SP2's DEP feature enabled to prevent virus damage, because the DEP to monitor a variety of programs to prevent viruses in protected memory locations to run harmful code. DEP through the processor's NX (No eXecute) feature, look for the memory not explicitly contains executable code in the data (these data are often the source code of the virus), find the data, NX them are marked as . If after a program in memory, trying to implement these with So, if you run a software that has been exposed, DEP will put the virus code marked as
If you want to give full play to DEP's protection, in addition to outside should upgrade to SP2, your CPU must also support the DEP technology. Currently common 32-bit processor (such as P4 Northwood, etc.) do not support NX, to support the technology, the main CPU 64-bit AMD processor (Athlon 64, AMD Opteron), and Intel's Itanium CPU, J Series P4 Prescott, is said to nVIDIA, VIA, Transmeta and other companies also plan to add the NX in its chip technology, but the pace of these companies updates NX too slow,
Microsoft Office 2007 Key, take some time before the official launch.
The method enable or disable DEP
By default, SP2 essential Windows programs and services only to enable the DEP. But you can also set up their own, so that all programs on the computer enabled DEP, in order to prevent the virus.
For example,
Office 2010 Standard, in addition to Acrobat Reader5.0, the make all programs and services enable DEP, method of operation is: Account login with administrator privileges SP2, and then click Click the ), click the
If you want to a program (such as Acrobat Reader 5.0) to disable DEP, you can click the above After the program is very vulnerable to attack, the virus can sneak into the program, and then spread to other programs on the computer and contacts in Outlook, and destroy your personal files. DEP is enabled, if any, after the program can not function properly, you can obtain the software vendor DEP-compatible version of the program, if no such version is to disable DEP.
In order to support DEP, P4 Prescott technique used EDB
In line with Microsoft's DEP feature, Intel for their CPU developed Currently Intel P4 Prescott (mPGA478 with LGA775 package) or for the C0 core stepping D0, the latest J Series P4 Prescott core with E0 stepping. Only J Series P4 Prescott with anti-virus function, only it really support EDB technology to meet the SP2's DEP antivirus feature that allows for buffer overflow (buffer overrun) Vulnerability in the design of the virus fail to prevent their replication and spread to other systems .
If you use a P4 Prescott / Celeron D (C0 stepping core) processors, upgraded to SP2, you will find a deadlock in the Windows XP operating system,
Purchase Windows 7, startup screen, but it will not be replaced by P4 Northwood this problem. This is because SP2 can open P4 Prescott (C0 stepping core) contains the EDB functions, but this type of CPU and the execution is not EDB, EDB part of its internal power transistor will not operate, and therefore cause the system to die lock. To solve this problem, Microsoft has released in the September 14 amendment to the relevant documents, we can go to Microsoft's official website to download. English version of Windows XP users to download address is download.microsoft.com/download/c/a/5/ca5f5398-2391-42e6-8b40-f6ec4db31c88/WindowsXP-KB885626-v2-x86-enu.exe, Windows XP Simplified Chinese version of the user Download download.microsoft.com/download/2/b/7/2b75ebbf-ce4c-4595-8ddf-4d45e4c1ca18/WindowsXP-KB885626-v2-x86-chs.exe
In order to support DEP, AMD 64-bit CPU using EVP techniques
AMD 64-bit processor the first to support Microsoft's DEP technologies. In order to meet the DEP, AMD and Microsoft to design research and development of AMD's new chips feature AMD 64-bit processors (including the Athlon 64/Athlon 64 FX / Athlon 64 mobile version / Sempron mobile version, etc.) will have the EVP. EVP and SP2's DEP feature technical cooperation, to prevent
However, in AMD 64 bit processor after SP2 installed on the machine, as long as your computer starts, the DEP feature, and configured the required driver files named Mpegport.sys hardware, when you use Sigma Design Company Realmagic Hollywood Plus DVD decoding software, they will conflict with the DEP. This is because older drivers are some similar operation with the virus, so SP2 to mistake it for the virus, which trigger the DEP, cause the computer to repeatedly restart. To solve this problem,
Microsoft Office 2010 Home And Business, Microsoft recommends that users update the older driver, or disable decoding software for the DEP, turn off the SP2 virus protection.