cannot be opened because its project type (.csproj) is not supported by this version of the application.

Go to Start> All Programs > Visual Studio 2008 > Visual Studio Tools > Click Visual Studio 2008 Command Prompt. Type the below command and press enter.

devenv.exe /resetskippkgs

SQL Delete current database

I need to delete my current database which I am using it , I googled around and found this answer:

http://sqlserver2000.databases.aspfaq.com/how-do-i-drop-a-sql-server-database.html

ALTER DATABASE myDataBase
    SET SINGLE_USER
    WITH ROLLBACK IMMEDIATE

DELETE DATABASE myDataBase 

C# difference between StringBuilder and String Object

The most common operation with string is concatenation, and this has to be performed very efficiently.
When we use String objects to concatenate two strings , then a new copy of string object is created in memory by adding two objects , and the old string object is deleted.

So we use StringBuilder to do it in a effective way, here the concatenation is done on the exsisting  string, hence the insertion is faster. Concatenation is done using Append() method

C# Shallow Copy and Deep Copy

http://www.codeproject.com/Articles/28952/Shallow-Copy-vs-Deep-Copy-in-NET 

Difference between null and String.Empty

1. string statement=null : means no object exists; null is not a value, it is a state indicating that object value is unknown or does not exists.

2. string statement = String.Empty : use of string.Empty doesn't create any objects  while "" creates a string object. So using string.Empty is better than using "" because every time you use "", it creates a new string while string.Empty just reference s string in memory that is created by default.

Understanding Reflection and static constructor

Hi .net newbies,
This post is mostly for you !!, to understand what  Reflection and static constructor really mean ,and when are they used in  .net projects.

You would have learnt what does .net reflection and static constructor mean , 

You may say reflection is :  The process of obtaining information about the assemblies and the types defined within them ,and creating and invoking and accessing type instance at run time and

You may say static constructor is used to initialize any static data or to perform a certain action that needs to be performed once.

So when do you use Reflection or static constructor, the below picture answers the question:

SQL Constraints

Constraints limit the type of  data that can go into the table.
The following are the constraints:

1. NOT NULL
2. UNIQUE
3. PRIMARY KEY
4. FOREIGN KEY
5. CHECK
6. DEFAULT

SQL Joins

Hi newbies,
Want to learn SQL joins at a glance!!, here you go... SQL joins is Venn diagram representation:
A very nice picture given in codeproject.

http://www.codeproject.com/Articles/33052/Visual-Representation-of-SQL-Joins

What are EXD files

EXD is control information cache file . It is a type of file that contains your most recently used information of a computer object , which in this case is a control

read more

OSI Model

http://home.earthlink.net/~tt4titans/id13.html
http://www.cse.iitk.ac.in/users/dheeraj/cs425/lec01.html
http://www.roseindia.net/technology/networking/osi.shtml

How to turn on Telnet client on your machine?

Here are the steps by which you can turn on the telnet client:
Goto Control panel ->     Programs and features ->      Turn Windows feature ON or OFF ->                                            Check Telnet Client ->     OK

HTTP Protocol

Nice tutorial on HTTP protocol:

Read here..