Delphi IDE is not visible

Question 1

Often this happens because you've got either a poorly behaving third-party component installed, or you've set the IDE to load the last project when it opens and it can't do that for some reason.

There are a few things that can help resolve this; they involve editing the shortcut to Delphi temporarily (or creating a new shortcut and modifying it instead, of course).

Edit the shortcut and add the -np parameter to the command line; it tells the IDE to not load a project on startup. If this works, you can try opening your project. If the IDE hangs again, rename your .dproj file to a different extension and open it with just the .dpr; the IDE will create a new .dproj file;
If the above doesn't work, edit the shortcut again, remove the -np, and replace it with -rFoo. This tells the IDE to load the Foo configuration from the registry on startup instead of the normal Delphi configuration. (Foo doesn't exist, so the IDE will create an all-new configuration in the registry named Foo, with no third-party components installed and all of the default settings for folders and options.) If this works, you can reinstall your third-party component sets one at a time to identify the problem package, and the edit the registry to remove it from your normal Delphi configuration.

Note: Foo in the second bullet point item above is just a name. It has no special meaning; it's just something that's commonly used as a dummy type or variable content. The parameter can be set to anything that doesn't already exist as a configuration in the Delphi registry settings; Bar, Dummy or Zombie will work just as well.

Once you've tried these (whether they fix the issue or not), don't forget to go back to remove the no longer needed command line parameter.

If none of the above works, a reinstall may be in order.

If you want to try a reinstall, uninstall the existing version (using the usual Control Panel Uninstall Software applet).

Doing an uninstall does not remove the registry keys, and a new install will see it exists and not create a new one, so you'll need to use RegEdit to delete the HKCU\Software\Embarcadero\BDS\10.0 tree (or rename it to something different like Old 10.0), and then reinstall Delphi. (As you're using other Delphi versions, make sure you leave those keys alone so you don't damage those installs. Only alter or delete the 10.0 tree.)

Question 2

In Delphi 4 and 5 it was the delphi32.dsk file. You can delete this file but you can also edit the file, section 'Main Window'. First kill the process in the taskmanager before you edit/delete this disk file.

[Main Window]
Create=1
Visible=0   <-- This value must be **1**
State=0
......
......

Start Delphi - et viola! It is back again.

Offtopic: Still running Delphi 5 on Windows 7, blazing fast, yes!