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中国DOS联盟论坛 » DOS学习入门 & 精彩文章 (教学室) » Half Repost "Comprehensive Guide to Cracking CMOS Passwords" DigestI View 20,573 Replies 58
Original Poster Posted 2002-10-21 00:00 ·  中国 江西 吉安 电信
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Full Guide to CMOS Password Cracking

"CMOS password" is what is commonly referred to as the "boot password", mainly to prevent others from using your own computer, setting up a barrier. (This article is only for when you forget it and should not be used for malicious purposes.)

There are many ways to crack the "CMOS password", mainly the following types:

1. Change Hardware Configuration
When you lose the CMOS password, you can first try to change the hardware configuration of the machine and then restart. Because if the system finds that the new hardware configuration is different from the original hardware configuration during startup, it may allow you to directly enter the CMOS for reconfiguration without the password. The method to change the hardware configuration is very simple: for example, remove a memory module or install a different model of CPU (of course, the motherboard needs to support it), replace a hard disk, etc.

2. Create Your Own Password Cracking File
A. When the system self-check is completed and you are about to boot Windows, press the F8 key, select "Safe mode command prompt only" (safe command mode), and then enter COPY CON YK.COM at the DOS prompt. After pressing Enter, enter the following in the editing environment:
ALT+179, ALT+55, ALT++136, ALT+216, ALT+230, ALT+112, ALT+176, ALT+32, ALT+230, ALT+113, ALT+254, ALT+195, ALT+128, ALT+251, ALT+64, ALT+117, ALT+241, ALT+195, and then press F6 to save. Note that when entering the above data, first press the ALT key, then press the number keys on the numeric keypad (pressing the number keys on the top row of the keyboard is useless). After entering a segment of numbers, release the ALT key, then press the ALT key again to enter the next segment of numbers... During the input process, a random character will appear on the screen every time you release the ALT key, and we don't need to care about it.
After saving and exiting, we directly run the YK.COM file. There should be no prompt information on the screen, and then restart the computer to clear the password in the CMOS. Of course, other settings in the CMOS will also be cleared at the same time, so we need to reconfigure them.
B. After selecting the safe command mode during startup, enter COPY CON YK.COM, and then enter the following in the editing environment:
ALT+176, ALT+17, ALT+230, p, ALT+176, ALT+20, ALT+230, q, ALT+205, space, and then press F6 to save. After running this file, restart the computer.

3. DEBUG Method
At the DOS prompt, run DEBUG and then enter:
—o70 18
—o71 18
—q
or
—o70 21
—o71 21
—q
After exiting to the DOS prompt, restart the computer to completely clear the CMOS password. Please note that 70 and 71 are two ports of the CMOS. We can randomly write some incorrect data (such as 20, 16, 17, etc.) to them, which will damage all settings in the CMOS. Friends with time may try more data.

4. Universal Password
If someone sets the security option in the COMS as the system, then every time you boot, you must enter the correct password. Otherwise, not only can you not enter Windows, but you can't even enter DOS. Then we can only rely on the universal password to solve the problem.
AMI BIOS: AMI; Sysg
AWARD BIOS: award; Syxz; h996; wantgirl; eBBB; dirrid.
The above universal passwords are almost always successful in cracking the CMOS password on 386, 486, and Pentium motherboards, but they are not so effective for PII-level or above motherboards. There are very few universal passwords that can crack new motherboards above PII, and almost no one has heard of them. However, the author found a password - abaubjao, which has successfully cracked the CMOS passwords on more than a dozen motherboards such as Chenqi 6ATA4 (PIII), Weige MVP4 (K6—2), Benz 160A, 160A+ (PIII), etc. and is not willing to keep it to himself, so he presents it to everyone here.

5. Use Tool Software
On the Internet, you will find that there are many software that can crack the CMOS password. The author thinks the best software is Biospwds, which is a small software made by a German. When using it, just gently click the "Get passwords" (obtain password) button, and your CMOS password will be displayed on the screen. In addition, you can also see the BIOS version, time, etc. Those with conditions can download it at www.geocities.com/mbockelkamp.

Note from the reprint: In fact, there are many good Cmos decryption software. Of course, most are Dos software.
Recommended: 1. cmos.com is only 630 bytes! It is most suitable to put it on the boot disk. Usage:
cmos /c /s /r (/c is to clear the password, /s is to save the cmos information to a file, /r is to restore the cmos information from the file.)
2. cmos.exe is 54904 bytes. I can't remember clearly. It can't be tested under win2000. So, sorry.
3. cmospwd.exe is 13035 bytes. The most useful and powerful tool to crack cmos. The previous cmos.com can only be regarded as bypassing the cmos password, but this one can calculate the password equivalent to your original set cmos password. (Due to the particularity of the cmos password, the calculated one may not be the same as your original set one, but it can be used the same. For specific introduction, please find relevant information by yourself to know why.)


6. Discharge
If you are too unlucky and can't crack the CMOS password with the above methods, then there is only this way. Open the motherboard manual, find the jumper to clear the CMOS settings, and change the method of its short circuit according to the manual to clear the CMOS. What, your motherboard is too old and there is no such jumper? Then take out the button battery on the motherboard. Why can't you boot after discharging? Put the battery back, silly!

[ Last edited by ko20010214 on 2008-10-22 at 00:50 ]
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Floor 2 Posted 2003-07-23 00:00 ·  中国 甘肃 兰州 电信
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Haha....
Good stuff!
Everyone, come and see!
Floor 3 Posted 2005-03-05 00:00 ·  中国 安徽 宿州 电信
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Not bad! Bump!
Floor 4 Posted 2005-03-14 00:00 ·  中国 湖北 武汉 电信
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Then take off the button battery on the mainboard. Why can't it boot after discharging? Just put the battery back, silly!

Hehe,,,,,,
Floor 5 Posted 2005-04-01 00:00 ·  中国 陕西 西安 电信
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Is it really that effective?
Floor 6 Posted 2005-06-14 00:00 ·  中国 贵州 贵阳 电信
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Not bad!

我爱电脑,更爱软件,最爱的是我的父母和老婆!
Floor 7 Posted 2005-06-27 00:00 ·  中国 河南 周口 电信
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Came in to review a bit
DOS不是万能的,但没有DOS万万不能…………
Floor 8 Posted 2005-10-09 00:16 ·  中国 广东 深圳 南山区 电信
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I've seen it on the Internet for countless times, and a large number of results come up when you search with GOOGLE.
Floor 9 Posted 2005-12-02 16:17 ·  中国 江西 抚州 电信
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This article is pretty good. VEVR supports it...! Post more in the future.
Floor 10 Posted 2005-12-02 22:40 ·  中国 湖北 武汉 电信
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Learn, thank you for sharing!
Floor 11 Posted 2005-12-04 17:04 ·  中国 福建 漳州 中移铁通
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Learned a lot!
Floor 12 Posted 2005-12-12 15:45 ·  中国 广东 广州 白云区 电信
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Yeah, there are plenty of them when you search with Google.
Floor 13 Posted 2005-12-16 10:37 ·  中国 陕西 渭南 电信
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The owner, this is a good thing. It's of great value.
Floor 14 Posted 2006-01-02 17:32 ·  中国 江苏 苏州 吴江区 电信
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Learn, thank you for sharing!
Floor 15 Posted 2006-01-02 19:33 ·  中国 上海 浦东新区 电信
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IV. Universal Password
If someone sets the security option in COMS to system, then every time you start the computer, you must enter the correct password. Otherwise, not only can't you enter Windows, but even DOS can't be entered. So we can only rely on the universal password to solve the problem.
AMI's BIOS: AMI; Sysg
AWARD's BIOS: award; Syxz; h996; wantgirl; eBBB; dirrid. What does this mean?
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