Disable USB Removable Mass Storage Device Drive Access in Windows

1. Run Registry Editor (regedit).
2. Navigate to the following registery key

   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UsbStor

3. In the right pane, double click on the Start value name.
4. Change the value data to 4 to disable the removable USB mass storage device drive access.
5. To revert and re-enable the drive access for removable USB mass storage device driver, change back the value data for Start to its original default of 3.

How to Hide and Loch Hardisk Drive In windows

1. Click on the "Start" button. Go to "Run", type "gpedit.msc" and press enter.
2. Wait for the "Group Policy" window to appear. Click on the "+" button behind "Administrative Templates". Then click the "+" button behind "Windows Components" and then "Windows Explorer".
3. Search for "Hide these specified drives in My Computer" in the options that appear in the right column of the window. Double click it, enable it and choose the drive(s) you want to hide.
4. Search for "Prevent access to drives from My Computer". Double click it and repeat the previous step if you want to stop accessing any drive by "command" (e.g, by typing "C:" in the address bar or "Run").
5. Close the group policy window.
6. Restart your computer for changes to take effect.

To Remove Drive Open with option

first go to run then write " regedit" that is registry
then find " ctrl+f"
in this box write "mountpoints2" and delete it ......
then again press "ctrl+f" again find mountpoints2 until all these files are not deleted
then u will see ur problems is solved................

How to install + Yum in Red Hat Enterprise Linux 4

Setting up the yum package manager is not required by everyone who downloads and installs Red Hat Enterprise Linux 4. If you will be using your Linux system on the U of S wireless network or other services that use the yum package manager, you need to complete this step. Red Hat Enterprise Linux 5 will use the yum package manager as the standard package manager.
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1. Download the following rpms from http://dag.wieers.com/packages/

• python-elementtree
• python-sqlite
• python-urlgrabber
• sqlite
• yum
• rpmforge-release

2. Install the rpms as root from the command line.
# rpm -Uvh python* sqlite* yum* rpmforge-release*
3. Add the ATrpms repository to your /etc/yum.conf by adding the following lines
   [atrpms]
   name=Red Hat Enterprise Linux $releasever - $basearch - ATrpms
   baseurl=http://dl.atrpms.net/el4-$basearch/atrpms/stable
   gpgkey=http://ATrpms.net/RPM-GPG-KEY.atrpms
   gpgcheck=1
4. Update the yum database.

yum update
Search the packages available from RHN.
yum search wine
Install packages
yum install wine

What does myisamchk do?

1. How do you start and stop MySQL on Windows? - net start MySQL, net stop MySQL
2. How do you start MySQL on Linux? - /etc/init.d/mysql start
3. Explain the difference between mysql and mysqli interfaces in PHP? - mysqli is the object-oriented version of mysql library functions.
4. What’s the default port for MySQL Server? - 3306
5. What does tee command do in MySQL? - tee followed by a filename turns on MySQL logging to a specified file. It can be stopped by command notee.
6. Can you save your connection settings to a conf file? - Yes, and name it ~/.my.conf. You might want to change the permissions on the file to 600, so that it’s not readable by others.
7. How do you change a password for an existing user via mysqladmin? - mysqladmin -u root -p password "newpassword"
8. Use mysqldump to create a copy of the database? - mysqldump -h mysqlhost -u username -p mydatabasename > dbdump.sql
9. Have you ever used MySQL Administrator and MySQL Query Browser? Describe the tasks you accomplished with these tools.
10. What are some good ideas regarding user security in MySQL? - There is no user without a password. There is no user without a user name. There is no user whose Host column contains % (which here indicates that the user can log in from anywhere in the network or the Internet). There are as few users as possible (in the ideal case only root) who have unrestricted access.
11. Explain the difference between MyISAM Static and MyISAM Dynamic. - In MyISAM static all the fields have fixed width. The Dynamic MyISAM table would include fields such as TEXT, BLOB, etc. to accommodate the data types with various lengths. MyISAM Static would be easier to restore in case of corruption, since even though you might lose some data, you know exactly where to look for the beginning of the next record.
12. What does myisamchk do? - It compressed the MyISAM tables, which reduces their disk usage.
13. Explain advantages of InnoDB over MyISAM? - Row-level locking, transactions, foreign key constraints and crash recovery.
14. Explain advantages of MyISAM over InnoDB? - Much more conservative approach to disk space management - each MyISAM table is stored in a separate file, which could be compressed then with myisamchk if needed. With InnoDB the tables are stored in tablespace, and not much further optimization is possible. All data except for TEXT and BLOB can occupy 8,000 bytes at most. No full text indexing is available for InnoDB. TRhe COUNT(*)s execute slower than in MyISAM due to tablespace complexity.
15. What are HEAP tables in MySQL? - HEAP tables are in-memory. They are usually used for high-speed temporary storage. No TEXT or BLOB fields are allowed within HEAP tables. You can only use the comparison operators = and <=>. HEAP tables do not support AUTO_INCREMENT. Indexes must be NOT NULL.
16. How do you control the max size of a HEAP table? - MySQL config variable max_heap_table_size.
17. What are CSV tables? - Those are the special tables, data for which is saved into comma-separated values files. They cannot be indexed.
18. Explain federated tables. - Introduced in MySQL 5.0, federated tables allow access to the tables located on other databases on other servers.
19. What is SERIAL data type in MySQL? - BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT
20. What happens when the column is set to AUTO INCREMENT and you reach the maximum value for that table? - It stops incrementing. It does not overflow to 0 to prevent data losses, but further inserts are going to produce an error, since the key has been used already.
21. Explain the difference between BOOL, TINYINT and BIT. - Prior to MySQL 5.0.3: those are all synonyms. After MySQL 5.0.3: BIT data type can store 8 bytes of data and should be used for binary data.
22. Explain the difference between FLOAT, DOUBLE and REAL. - FLOATs store floating point numbers with 8 place accuracy and take up 4 bytes. DOUBLEs store floating point numbers with 16 place accuracy and take up 8 bytes. REAL is a synonym of FLOAT for now.
23. If you specify the data type as DECIMAL (5,2), what’s the range of values that can go in this table? - 999.99 to -99.99. Note that with the negative number the minus sign is considered one of the digits.
24. What happens if a table has one column defined as TIMESTAMP? - That field gets the current timestamp whenever the row gets altered.
25. But what if you really want to store the timestamp data, such as the publication date of the article? - Create two columns of type TIMESTAMP and use the second one for your real data.
26. Explain data type TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP - The column exhibits the same behavior as a single timestamp column in a table with no other timestamp columns.
27. What does TIMESTAMP ON UPDATE CURRENT_TIMESTAMP data type do? - On initialization places a zero in that column, on future updates puts the current value of the timestamp in.
28. Explain TIMESTAMP DEFAULT ‘2006:09:02 17:38:44′ ON UPDATE CURRENT_TIMESTAMP. - A default value is used on initialization, a current timestamp is inserted on update of the row.
29. If I created a column with data type VARCHAR(3), what would I expect to see in MySQL table? - CHAR(3), since MySQL automatically adjusted the data type.