There could be several causes to this problem:
1- Corrupt directory or path in the properties of the shortcut. Make new shortcut from source file:
Excel.exe in Microsoft Office and rename to desktop name.
2- Installer is corrupt. Check with regedit following registry entries:
[HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Common\General\InstallProductID]
@="{00000409-78E1-11D2-B60F-006097C998E7}"
[HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Common\LanguageResources]
"1033"="On"
"HelpLanguage"=dword:00000409
"InstallLanguage"=dword:00000409
"UILanguage"=dword:00000409
[HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Common\LanguageResources]
"1033"="Off"
"2057"="On"
"HelpLanguage"=dword:00000409
"InstallLanguage"=dword:00000409
"UILanguage"=dword:00000409
[HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Common\UserInfo]
-"UserInitials"
-"UserName"
[HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Common\UserInfo]
-"UserInitials"
-"UserName"
[HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Access]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Access]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Common]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Common]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Excel]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Excel]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Outlook]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\PowerPoint]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\PowerPoint]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\Word]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Word]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\9.0\FrontPage]
"UserData"=dword:00000001
[HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\FrontPage]
"UserData"=dword:00000001
3- A conflict in settings and application. Open Excel-programme, Tools, Supplements. Uncheck the box of Euro Conversion. Close and re-open.
Source: a forum at Annoyances.org. Read further on more variants of installer and Office applications conflicts.
4-Microsoft also says on this topic in:
Windows Installer Appears Every Time a Program Is Started (Office 2000) - a similar case