The number of open file descriptors on Windows is limited to a maximum of 2048, which may limit the ability to open a large number of tables simultaneously. This limit is due to the compatibility functions used to open files on Windows that use the POSIX compatibility layer.

This limitation will also cause problems if you try to set open_files_limit to a value greater than the 2048 file limit.

On Windows 32-bit platforms it is not possible to use more than 2GB of RAM within a single process, including MySQL. This is because the physical address limit on Windows 32-bit is 4GB and the default setting within Windows is to split the virtual address space between kernel (2GB) and user/applications (2GB).

To use more memory than this you will need to use a 64-bit version of Windows.

When using MyISAM tables, you cannot use aliases within Windows link to the data files on another volume and then link back to the main MySQL datadir location.

This facility is often used to move the data and index files to a RAID or other fast solution, while retaining the main .FRM files in the default data directory configured with the datadir option.

The timers within MySQL used on Windows are of a lower precision than the timers used on Linux. For most situations you may not notice a difference, but the delay implied by a call to SLEEP() on Windows and Linux may differ slightly due to the differences in precision.

There is no 64-bit OLEDB Provider for ODBC (MSDASQL) in any 64-bit Windows operating system up to and including Windows Vista. In practical terms this means that you can't use the MySQL ODBC driver from ADO and other users of OLEDB.