Problems encountered in MySQL Server 5.5 installation and how to resolve them

Before beginning with senior used computer work, all kinds of do not adapt, began to re-build their habits of the environment, reinstall MySQL is one of them, and then reinstall the process encountered problems, the specific situation summarized as follows:

1. Previously also reinstalled MySQL, but did not use the direct uninstall, and then reinstall, no problems.

2. Previously installed, and then built a table in it to test, and then uninstall, delete the installation directory,... Re-install the "Unable to start the MySQL service" error occurred ....

The following are the resolution procedures:

How to find it on the Internet
1) Reinstall several times, changed the version is not ...
2) Search from the Internet, find the solution is: Find the MySQL installation directory under the My.ini configuration file, and then put the inside of Default-storage-engine = InnoDB modified to Default-storage-engine=myisam
Can actually start the MySQL service.
But the original database files are not used, because the storage method is different (as if ...)

The solution to my own rethinking:

According to the above method I opened the database, found that the original database files exist, that is, even if the MySQL installation directory is deleted, the database storage files still exist. So, all kinds of data in the database mentioned in the network exist in the installation directory, is not correct.
I want to find these database repository files and then delete them or cut them somewhere else. Then reinstall MySQL should be ready.
I am directly on the entire hard drive (in fact, the C drive and the installed disk can be) search for the keyword "MySQL". And then found a C:\programData folder (Note: The folder is a hidden folder, you need to set visible or directly in the path to enter the full path to see), There is a MySQL directory under this folder, and there are different versions of the stored files that store the MySQL database data that you used to install. I found myself in there. The T_users form file that was created under the test database.
Then I deleted the entire MySQL folder and cut it somewhere else.
Then reinstall it to start the MySQL service as normal. If you need the previous database files, then put back should also be able to, I did not try, so not very sure ...

(⊙o⊙) ... Like 5.5 and after MySQL in Win7, the data in the installation directory only stores the structure files of some databases, and the database files are stored in the C:\programData folder.

Note: My OS is WIN7 (x64), MySQL version is Server 5.5

Problems encountered in MySQL Server 5.5 installation and how to resolve them