Sorted:

Solution to the Win7 system prompting “Cannot find d3d10level9.dll” file.

What should I do if the system is missing COMDLG32.OCX?

How to enter root mode and install gcc on Ubuntu

Common encryption and decryption methods in C# (MD5 encryption and decryption)

Detailed guide on installing and configuring Tomcat

How to install gcc on Ubuntu?

In-depth tutorial for installing the Android SDK

Explanation of the android:scaleType property

Reasons and solutions for the appearance of werfault.exe

What should you do if the openal32.dll file is missing from your computer?