config.sys

The config.sys file is a configuration file that Windows 95, Windows 98, and Windows ME (hereafter referred to as the Win9x family) use to
setup the environment when they load. It's usually located in the root
of the system drive like C:\config.sys.

For Windows NT 4.0, Windows 2000, and Windows XP (hereafter referred to as the WinNT family), the config.nt file is used instead. Unlike the Win9x family, the settings in the config.nt file only apply to DOS programs and 16-bit Windows applications, but not 32-bit
Windows applications in the WinNT family. It's located in the
system32 folder like C:\winnt\system32\config.nt or C:\windows\system32\config.nt.

There is only one line that we're going to worry about- "Files=". The "Files=" line determines how many files can be open simultaneously. This is also referred to as the file handles setting. This should be set to 150. Frequently, it's set too low to something like 20 or 40. It sounds like overkill to the average user because they think that they'll never have 20 files open simultaneously. However, the operating system and applications that are running will frequently have files open behind the scenes that the user isn't aware of. Database programs are the worst for file handle usage. It's not uncommon for a database-oriented program to have 80 to 120 files open in the background simultaneously.

If you are running a program (especially a database program) and it suddenly freezes up when you go to access a particular menu option or function, it could be that the files setting is too low. If the program is trying to open another file but the file handle limit has been already been reached, the program will frequently freeze up. If the programmer had done his/her job properly, the programmer should give you an error message stating something like too files were open. Unfortunately, this frequently isn't the case.

To make the change, you can browse to the file using Windows Explorer or My Computer, right-click on the file and select "Open With" and select NotePad from the program list. In the Win9x family you can also run the SysEdit utility (Start -> Run -> sysedit) and select the Config.sys pane to edit the file.

If the "Files=" line exists, make sure that the number is set to 150, so that it is "Files=150". If the "Files=" line doesn't exist, create it as "Files=150". Save your settings and exit. The setting will take effect the next time that the computer is rebooted.