I just tried to reinstall MySQL 5.5x on Windows 7. But it fails at the point where it tries to start MySQL Service i.e ‘start service’ step.
1. Uninstall MySQL. (Control Panel > Add Remove Programs)
2. Remove any MySQL Service if existing (: sc delete MySQL).
3. This is the most important step(who would have imagined!) – and the one that causes reinstall failure:
On Windows7 delete this hidden dir: c:\programdata\MySQL
This dir contains some log files etc – which causes the reinstall to fail. On Windows Vista/XP etc.. there would be a equivalent dir too (perhaps in another location).
On Windows XP, you should delete this directory:
C:\Documents and Settings\All Users\Application Data\MySQL.