首先：我知道这个问题已经成千上万次了。但是我在过去四个小时内发现的所有给定答案都无法解决我的特定问题，我在这里疯了。我将非常感谢您的帮助和建议！
尝试编译包含 \ includegraphics 命令的非常简单的.tex文件，最终出现“找不到文件”错误。以下面的例子为例：
\documentclass{report}
\usepackage{graphicx}
\begin{document}
\includegraphics{b}
\end{document}
图像文件实际上只是被称为“ b.jpg”（同时），并且肯定与tex文件位于同一路径。在命令中添加“ .jpg”不会改变任何事情。调用图形而不是 graphicx 都不会。
创建的输出文件包含以下内容：
This is pdfTeX, Version 3.14159265-2.6-1.40.20 (MiKTeX 2.9.7200 64-bit) (preloaded format=pdflatex 2019.10.6) 6 OCT 2019 17:25 entering extended mode
**"C:/Neuer Ordner/test.tex" ("C:/Neuer Ordner/test.tex" LaTeX2e <2018-12-01> ("C:\Program Files\MiKTeX 2.9\tex/latex/base\article.cls" Document Class: article 2019/08/27 v1.4j Standard LaTeX document class ("C:\Program Files\MiKTeX 2.9\tex/latex/base\size10.clo" File: size10.clo 2019/08/27 v1.4j Standard LaTeX file (size option) ) \c@part=\count80 \c@section=\count81 \c@subsection=\count82 \c@subsubsection=\count83 \c@paragraph=\count84 \c@subparagraph=\count85 \c@figure=\count86 \c@table=\count87 \abovecaptionskip=\skip41 \belowcaptionskip=\skip42 \bibindent=\dimen102 ) ("C:\Program Files\MiKTeX
2.9\tex/latex/graphics\graphics.sty" Package: graphics 2019/07/20 v1.3b Standard LaTeX Graphics (DPC,SPQR)
("C:\Program Files\MiKTeX 2.9\tex/latex/graphics\trig.sty" Package: trig 2016/01/03 v1.10 sin cos tan (DPC) ) ("C:\Program Files\MiKTeX
2.9\tex/latex/graphics-cfg\graphics.cfg" File: graphics.cfg 2016/06/04 v1.11 sample graphics configuration ) Package graphics Info: Driver file: pdftex.def on input line 105.
("C:\Program Files\MiKTeX 2.9\tex/latex/graphics-def\pdftex.def" File: pdftex.def 2018/01/08 v1.0l Graphics/color driver for pdftex )) (test.aux) \openout1 = `test.aux'.
LaTeX Font Info: Checking defaults for OML/cmm/m/it on input line
4. LaTeX Font Info: ... okay on input line 4. LaTeX Font Info: Checking defaults for T1/cmr/m/n on input line 4. LaTeX Font Info: ... okay on input line 4. LaTeX Font Info: Checking defaults for OT1/cmr/m/n on input line 4. LaTeX Font Info: ... okay on input line 4. LaTeX Font Info: Checking defaults for OMS/cmsy/m/n on input line 4. LaTeX Font Info: ... okay on input line 4. LaTeX Font Info: Checking defaults for OMX/cmex/m/n on input line 4. LaTeX Font Info: ... okay on input line 4. LaTeX Font Info: Checking defaults for U/cmr/m/n on input line 4. LaTeX Font Info: ... okay on input line 4.
(C:\Users\rB\AppData\Roaming\MiKTeX\2.9\tex/context/base/mkii\supp-pdf.mkii [Loading MPS to PDF converter (version 2006.09.02).] \scratchcounter=\count88 \scratchdimen=\dimen103 \scratchbox=\box27 \nofMPsegments=\count89 \nofMParguments=\count90 \everyMPshowfont=\toks14 \MPscratchCnt=\count91 \MPscratchDim=\dimen104 \MPnumerator=\count92 \makeMPintoPDFobject=\count93 \everyMPtoPDFconversion=\toks15 ) ("C:\Program Files\MiKTeX 2.9\tex/latex/oberdiek\epstopdf-base.sty" Package: epstopdf-base 2016/05/15 v2.6 Base part for package epstopdf
("C:\Program Files\MiKTeX 2.9\tex/generic/oberdiek\infwarerr.sty" Package: infwarerr 2016/05/16 v1.4 Providing info/warning/error messages (HO) ) ("C:\Program Files\MiKTeX
2.9\tex/latex/oberdiek\grfext.sty" Package: grfext 2016/05/16 v1.2 Manage graphics extensions (HO)
("C:\Program Files\MiKTeX 2.9\tex/generic/oberdiek\kvdefinekeys.sty" Package: kvdefinekeys 2016/05/16 v1.4 Define keys (HO)
("C:\Program Files\MiKTeX 2.9\tex/generic/oberdiek\ltxcmds.sty" Package: ltxcmds 2016/05/16 v1.23 LaTeX kernel commands for general use (HO) ))) ("C:\Program Files\MiKTeX
2.9\tex/latex/oberdiek\kvoptions.sty" Package: kvoptions 2016/05/16 v3.12 Key value format for package options (HO)
("C:\Program Files\MiKTeX 2.9\tex/latex/graphics\keyval.sty" Package: keyval 2014/10/28 v1.15 key=value parser (DPC) \KV@toks@=\toks16 ) ("C:\Program Files\MiKTeX 2.9\tex/generic/oberdiek\kvsetkeys.sty" Package: kvsetkeys 2016/05/16 v1.17 Key value parser (HO)
("C:\Program Files\MiKTeX 2.9\tex/generic/oberdiek\etexcmds.sty" Package: etexcmds 2016/05/16 v1.6 Avoid name clashes with e-TeX commands (HO)
("C:\Program Files\MiKTeX 2.9\tex/generic/oberdiek\ifluatex.sty" Package: ifluatex 2016/05/16 v1.4 Provides the ifluatex switch (HO) Package ifluatex Info: LuaTeX not detected. )))) ("C:\Program Files\MiKTeX 2.9\tex/generic/oberdiek\pdftexcmds.sty" Package: pdftexcmds 2019/07/25 v0.30 Utility functions of pdfTeX for LuaTeX (HO )
("C:\Program Files\MiKTeX 2.9\tex/generic/oberdiek\ifpdf.sty" Package: ifpdf 2018/09/07 v3.3 Provides the ifpdf switch ) Package pdftexcmds Info: LuaTeX not detected. Package pdftexcmds Info: \pdf@primitive is available. Package pdftexcmds Info: \pdf@ifprimitive is available. Package pdftexcmds Info: \pdfdraftmode found. ) Package epstopdf-base Info: Redefining graphics rule for `.eps' on input line 4
38. Package grfext Info: Graphics extension search list: (grfext) [.pdf,.png,.jpg,.mps,.jpeg,.jbig2,.jb2,.PDF,.PNG,.JPG,.JPE G,.JBIG2,.JB2,.eps] (grfext) \AppendGraphicsExtensions on input line 456. ) ! Undefined control sequence. \Ginclude@graphics ...\Ginput@path \set@curr@file
{#1}\edef \uq@curr@file {\... l.5 \includegraphics{b}
The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g., `\hobx'), type `I' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined.
! Undefined control sequence. \Ginclude@graphics ...e \expandafter {\@curr@file
}}\expandafter \filename@p... l.5 \includegraphics{b}
The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g., `\hobx'), type `I' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined.
! Undefined control sequence. <recently read> \unquote@name
l.5 \includegraphics{b}
The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g., `\hobx'), type `I' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined.
! Undefined control sequence. <recently read> \quote@name
l.5 \includegraphics{b}
The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g., `\hobx'), type `I' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined.
! Undefined control sequence. <recently read> \quote@name
l.5 \includegraphics{b}
The control sequence at the end of the top line of your error message was never \def'ed. If you have misspelled it (e.g., `\hobx'), type `I' and the correct spelling (e.g., `I\hbox'). Otherwise just continue, and I'll forget about whatever was undefined.
! LaTeX Error: File `b' not found.
See the LaTeX manual or LaTeX Companion for explanation. Type H <return> for immediate help. ...
l.5 \includegraphics{b}
I could not locate the file with any of these extensions: .pdf,.png,.jpg,.mps,.jpeg,.jbig2,.jb2,.PDF,.PNG,.JPG,.JPEG,.JBIG2,.JB2,.eps Try typing <return> to proceed. If that doesn't work, type X <return> to quit.
[1
{C:/Users/rB/AppData/Local/MiKTeX/2.9/pdftex/config/pdftex.map}] (test.aux) ) Here is how much of TeX's memory you used: 1367 strings out of 492895 19199 string characters out of 3133488 80095 words of memory out of 3000000 5293 multiletter control sequences out of 15000+200000 3640 words of font info for 14 fonts, out of 3000000 for 9000 1141 hyphenation exceptions out of 8191 41i,4n,25p,289b,107s stack positions out of 5000i,500n,10000p,200000b,50000s <C :/Program Files/MiKTeX 2.9/fonts/type1/public/amsfonts/cm/cmr10.pfb> Output written on test.pdf (1 page, 10121 bytes). PDF statistics: 10 PDF objects out of 1000 (max. 8388607) 0 named destinations out of 1000 (max. 500000) 1 words of extra memory for PDF output out of 10000 (max. 10000000)
即使我明确选择了 pdflatex ，为什么它以“ This is pdfTeX”开头？这可能是这里的关键吗？ 我在TeXnicCenter 2.02中使用pdflatex，在Win10 64位中使用MikTex 2.9。已经尝试重新安装MikTex。
在此先感谢您的帮助！