解决方案：

打开excel，依次选择：工具-选项-常规-设置-忽略其他应用程序的勾去掉。

初步估计是病毒把excel文件的“打开”设置更改了。

如果还不行，可以尝试将下列红字部分复制到记事本内，保存为excel.reg，然后双击添加到注册表。然后再按上述步骤操作。

Windows Registry Editor Version 5.00

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE]

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell] @="Open"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\New] @="新建(&N)"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\New\command] @="\"C:\\Program Files\\Microsoft Office\\OFFICE11\\EXCEL.EXE\" /e /n" "command"=hex(7):26,00,69,00,67,00,41,00,56,00,6e,00,2d,00,7d,00,66,00,28,00,\   5a,00,58,00,66,00,65,00,41,00,52,00,36,00,2e,00,6a,00,69,00,45,00,58,00,43,\   00,45,00,4c,00,46,00,69,00,6c,00,65,00,73,00,3e,00,21,00,44,00,65,00,40,00,\   5d,00,56,00,7a,00,28,00,72,00,3d,00,66,00,60,00,31,00,6c,00,66,00,71,00,60,\   00,3f,00,52,00,26,00,20,00,2f,00,65,00,20,00,2f,00,6e,00,00,00,00,00

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\New\ddeexec] @="[new(\"%1\")]"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\New\ddeexec\application] @="Excel"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\New\ddeexec\topic] @="system"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Open] @="打开(&O)"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Open\command] @="\"C:\\Program Files\\Microsoft Office\\OFFICE11\\EXCEL.EXE\" /e" "command"=hex(7):26,00,69,00,67,00,41,00,56,00,6e,00,2d,00,7d,00,66,00,28,00,\   5a,00,58,00,66,00,65,00,41,00,52,00,36,00,2e,00,6a,00,69,00,45,00,58,00,43,\   00,45,00,4c,00,46,00,69,00,6c,00,65,00,73,00,3e,00,21,00,44,00,65,00,40,00,\   5d,00,56,00,7a,00,28,00,72,00,3d,00,66,00,60,00,31,00,6c,00,66,00,71,00,60,\   00,3f,00,52,00,26,00,20,00,2f,00,65,00,00,00,00,00

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Open\ddeexec] @="[open(\"%1\")]"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Open\ddeexec\application] @="Excel"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Open\ddeexec\topic] @="system"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\OpenAsReadOnly] @="以只读方式打开" "Extended"=""

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\OpenAsReadOnly\command] @="\"C:\\Program Files\\Microsoft Office\\OFFICE11\\EXCEL.EXE\" /h /e" "command"=hex(7):26,00,69,00,67,00,41,00,56,00,6e,00,2d,00,7d,00,66,00,28,00,\   5a,00,58,00,66,00,65,00,41,00,52,00,36,00,2e,00,6a,00,69,00,45,00,58,00,43,\   00,45,00,4c,00,46,00,69,00,6c,00,65,00,73,00,3e,00,21,00,44,00,65,00,40,00,\   5d,00,56,00,7a,00,28,00,72,00,3d,00,66,00,60,00,31,00,6c,00,66,00,71,00,60,\   00,3f,00,52,00,26,00,20,00,2f,00,68,00,20,00,2f,00,65,00,00,00,00,00

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\OpenAsReadOnly\ddeexec] @="[open(\"%1\",,,,,,,,,,,,,,1,,1)]"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\OpenAsReadOnly\ddeexec\application] @="Excel"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\OpenAsReadOnly\ddeexec\topic] @="system"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Print] @="打印(&P)"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Print\command] @="\"C:\\Program Files\\Microsoft Office\\OFFICE11\\EXCEL.EXE\" /e" "command"=hex(7):26,00,69,00,67,00,41,00,56,00,6e,00,2d,00,7d,00,66,00,28,00,\   5a,00,58,00,66,00,65,00,41,00,52,00,36,00,2e,00,6a,00,69,00,45,00,58,00,43,\   00,45,00,4c,00,46,00,69,00,6c,00,65,00,73,00,3e,00,21,00,44,00,65,00,40,00,\   5d,00,56,00,7a,00,28,00,72,00,3d,00,66,00,60,00,31,00,6c,00,66,00,71,00,60,\   00,3f,00,52,00,26,00,20,00,2f,00,65,00,00,00,00,00

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Print\ddeexec] @="[open(\"%1\")][print()][close()]"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Print\ddeexec\application] @="Excel"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Print\ddeexec\ifexec] @="[open(\"%1\")][print()][quit()]"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Print\ddeexec\topic] @="system"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Printto]

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Printto\command] @="\"C:\\Program Files\\Microsoft Office\\OFFICE11\\EXCEL.EXE\" /e" "command"=hex(7):26,00,69,00,67,00,41,00,56,00,6e,00,2d,00,7d,00,66,00,28,00,\   5a,00,58,00,66,00,65,00,41,00,52,00,36,00,2e,00,6a,00,69,00,45,00,58,00,43,\   00,45,00,4c,00,46,00,69,00,6c,00,65,00,73,00,3e,00,21,00,44,00,65,00,40,00,\   5d,00,56,00,7a,00,28,00,72,00,3d,00,66,00,60,00,31,00,6c,00,66,00,71,00,60,\   00,3f,00,52,00,26,00,20,00,2f,00,65,00,00,00,00,00

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Printto\ddeexec] @="[open(\"%1\")][print(1,,,,,,,,,,,2,\"%2\")][close()]"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Printto\ddeexec\application] @="Excel"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Printto\ddeexec\ifexec] @="[open(\"%1\")][print(1,,,,,,,,,,,2,\"%2\")][quit()]"

[HKEY_CLASSES_ROOT\Applications\EXCEL.EXE\shell\Printto\ddeexec\topic] @="system"