1. If the system prompts a similar prompt, such as missing or missing mspdb100.dll, when running a software or compiling program, copy the downloaded mspdb100.dll to the specified directory (usually in the system directory or in the Software Directory at the same level), or re-Add the file reference. 3. Select the file version based on the software. This step is complex. If it is a Windows dll file, the version number starts with 5.0 or contains nt files that are generally windows2000. Windows xp files whose versions start with 5.1 or contain xp, xp SP1, xp SP2, and xp SP3 information. Files whose versions start with 6.0 or contain longhorn and vista are generally Windows vista files. Files whose versions start with 6.1 or contain win7 information are generally Windows 7 files. If it is not a windows dll file, you need to flexibly view the version number, description, information provided by netizens, and the version number of the related dll to judge. Copy mspdb100.dll directly to the System directory: 1. Windows 95/98/Me System, and copy mspdb100.dll to the C: \ Windows \ System directory. 2. in Windows NT/2000, copy mspdb100.dll to the C: \ WINNT \ System32 directory. 3. In Windows XP/WIN7/Vista, copy mspdb100.dll to the C: \ Windows \ System32 directory. 4. If your system is 64-bit, copy the file to C: \ Windows \ SysWOW64 directory contains the registration bat file of the 32 system (replace system32 with SysWOW64 in 64-Bit mode .) The copy code is as follows: @ echo starts to register copy mspdb100.dll % windir % \ system32 \ regsvr32 % windir % \ system32 \ mspdb100.dll/s @ echo mspdb100.dll is successfully registered @ pause