All you did was to update the font size and save the file, then go to open the TBrowser again, right. By the way my rootrc file in my installation folder. Does anything look wrong?
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# @(#)root/config:$Id$
# Author: Fons Rademakers  22/09/95

# ROOT Environment settings are handled via the class TEnv. To see
# which values are active do: gEnv->Print().

# Path used by dynamic loader to find shared libraries.
# This path will be appended to the (DY)LD_LIBRARY_PATH on Unix
# and to PATH on Windows.
# Paths are different for Unix and Windows. The example shows the defaults
# for all ROOT applications for either Unix or Windows.
#Unix.*.Root.DynamicPath:    .:$(ROOTSYS)/lib
#WinNT.*.Root.DynamicPath:   .;$(ROOTSYS)/bin

# Path used to find macros.
# Paths are different for Unix and Windows. The example shows the defaults
# for all ROOT applications for either Unix or Windows.
#Unix.*.Root.MacroPath:      .:$(ROOTSYS)/macros
#WinNT.*.Root.MacroPath:     .;$(ROOTSYS)/macros

# Path used to find plugin macros.
# Paths are different for Unix and Windows. The example shows the defaults
# for all ROOT applications for either Unix or Windows.
#Unix.*.Root.PluginPath:     $(ROOTSYS)/etc/plugins
#WinNT.*.Root.PluginPath:    $(ROOTSYS)/etc/plugins

# Path where to look for TrueType fonts.
Unix.*.Root.UseTTFonts:     true
#*.*.Root.TTFontPath:        $(ROOTSYS)/fonts

# Use Net* API functions.
WinNT.UseNetAPI:         true

# Use thread library (if exists).
Unix.*.Root.UseThreads:     false

# Select the compression algorithm (0=old zlib, 1=new zlib)
# Note, setting this to `0' may be a security vulnerability.
Root.ZipMode:            1

# Show where item is found in the specified path.
Root.ShowPath:           false

# Activate malloc/new, free/delete calls via the TMemStat class
# the parameter buffersize is the number of calls to malloc or free that can be stored in one memory buffer.
# when the buffer is full, the calls to malloc/free pointing to the same location
# are eliminated and not written to the final Tree. The default value 100000
# is such that between 50 and 90% of the calls are eliminated depending on the application.
# the parameter TMemStat.maxcalls is the maximum number of new/delete calls to be monitored
# 5 million calls is a reasonable number.
# if your code has been compiled with -fno-omit-frame-pointer you can specify
# gnubuiltin for Root.TMemStat.system. In this case the backtrace is much faster.
Root.TMemStat:            0
Root.TMemStat.buffersize: 100000
Root.TMemStat.maxcalls:   5000000
#Root.TMemStat.system:    gnubuiltin
Root.TMemStat.system:

# Activate memory statistics (size and cnt is used to trap allocation of
# blocks of a certain size after cnt times).
Root.MemStat:            0
Root.MemStat.size:      -1
Root.MemStat.cnt:       -1
Root.ObjectStat:         0

# Activate memory leak checker (use in conjunction with $ROOTSYS/bin/memprobe).
# Currently only works on Linux with gcc.
Root.MemCheck:           0
Root.MemCheckFile:       memcheck.out

# Global debug mode. When >0 turns on progressively more details debugging.
Root.Debug:              0
Root.ErrorHandlers:      1
Root.Stacktrace:         yes
# Allow for a customized backtrace script.
#Root.StacktraceScript:   $(ROOTSYS)/etc/gdb-backtrace.sh
# Allow for a customized backtrace messages (e.g. referencing your own project
# bug tracking system). Change this message rather then the entire script.
# The % characters will be replaced by newlines.
#Root.StacktraceMessage:  The lines below might hint at the cause of the crash.%If they do not help you then please submit a bug report at%http://myproject/bugs. Please post the ENTIRE stack trace%from above as an attachment in addition to anything else%that might help us fixing this issue.

# Ignore errors lower than the ignore level. Possible values:
# Print, Info, Warning, Error, Break, SysError and Fatal.
Root.ErrorIgnoreLevel:   Print

# Settings for X11 behaviour.
X11.Sync:                no
X11.FindBestVisual:      yes
X11.UseXft:              no
X11.XInitThread:         yes

# Settings for Cocoa backend.
# The EnableAntiAliasing flag defines if you want to have anti-aliased
# lines/polygon in a canvas/pad. Possible values:
# yes (enable AA), no (disable AA) and auto (use AA only on Retina displays)
# There is a special flag EnableFillAreaAntiAliasing for fill area which is "no"
# by default because antialiasing for fill area may create artificial meshes on on plots
Cocoa.EnableAntiAliasing: yes
Cocoa.EnableFillAreaAntiAliasing: no

# Settings for Win32 behavior.
Win32.UseSysPointers:    no

# Default editor.
Unix.*.Editor:           vi
WinNT.*.Editor:          notepad

# Default 3d Viewer.
# By default 3-D views are shown in the pad,
# if the next line is activated, the default viewer will be OpenGL.
#Viewer3D.DefaultDrawOption:   ogl

# Default Fitter (current choices are Minuit and Fumili).
Root.Fitter:             Minuit

# Enable (default) or disable the RooFit banner printing.
# RooFit.Banner:  yes

# Specify list of file endings which TTabCom (TAB completion) should ignore.
#TabCom.FileIgnore:       .cpp:.h:.cmz

# TCanvas specific settings. Opaque move and resize show full pad during
# the operation instead of only the outline. In case you have a really very
# old graphics card turn these options off. UseScreenFactor=true means to
# size canvas according to size of screen, so a canvas still looks good on a
# low resolution laptop screen without having to change canvas size in macros.
# HighLightColor 2 = red. ShowEventStatus allows the event status bar to
# be turned on by default. AutoExec allows TExec objects to be executed
# on mouse and key events.
Canvas.MoveOpaque:          true
Canvas.ResizeOpaque:        true
Canvas.ShowGuideLines:      true
Canvas.UseScreenFactor:     false
Canvas.HighLightColor:      2
Canvas.ShowEventStatus:     false
Canvas.ShowToolTips:        false
Canvas.ShowToolBar:         false
Canvas.ShowEditor:          false
Canvas.AutoExec:            true
Canvas.PrintDirectory:      .
# Set the default precision when writing floating point numbers in
# TCanvas::SaveSource
Canvas.SavePrecision:       7
# Set the default TStyle
# Predefined styles are: Plain, Bold, Video, Pub, Classic, Modern.
Canvas.Style:               Modern
# Default file format to be used in the Canvas "Save As" dialog
Canvas.SaveAsDefaultType    pdf

# Printer settings.
#WinNT.*.Print.Command:      AcroRd32.exe
#Unix.*.Print.Command:       a2ps -P%p --landscape --columns=2 --margin=30 -rf8.0 %f
#Print.Printer:              32-rb20-hp
#Print.Directory:            .
#Print.FileType:             pdf

# Default histogram binnings for TTree::Draw().
Hist.Binning.1D.x:          100

Hist.Binning.2D.x:           40
Hist.Binning.2D.y:           40
Hist.Binning.2D.Prof:       100

Hist.Binning.3D.x:           20
Hist.Binning.3D.y:           20
Hist.Binning.3D.z:           20
Hist.Binning.3D.Profx:      100
Hist.Binning.3D.Profy:      100

# Default histogram precision for TTree::Draw(). It can be 'float"or "double"
Hist.Precision.1D:           float
Hist.Precision.2D:           float
Hist.Precision.3D:           float

# Default statistics parameters names.
Hist.Stats.Entries:          Entries
Hist.Stats.Mean:             Mean
Hist.Stats.MeanX:            Mean x
Hist.Stats.MeanY:            Mean y
Hist.Stats.MeanZ:            Mean z
Hist.Stats.StdDev:           Std Dev
Hist.Stats.StdDevX:          Std Dev x
Hist.Stats.StdDevY:          Std Dev y
Hist.Stats.StdDevZ:          Std Dev z
Hist.Stats.Underflow:        Underflow
Hist.Stats.Overflow:         Overflow
Hist.Stats.Integral:         Integral
Hist.Stats.IntegralBinWidth: Integral(w)
Hist.Stats.Skewness:         Skewness
Hist.Stats.SkewnessX:        Skewness x
Hist.Stats.SkewnessY:        Skewness y
Hist.Stats.SkewnessZ:        Skewness z
Hist.Stats.Kurtosis:         Kurtosis
Hist.Stats.KurtosisX:        Kurtosis x
Hist.Stats.KurtosisY:        Kurtosis y
Hist.Stats.KurtosisZ:        Kurtosis z

# THtml specific settings (for more see doc of THtml class).
Root.Html.SourceDir:    .
Root.Html.Root:         http://root.cern.ch/root/html
Root.Html.ViewCVS:      http://root.cern.ch/viewcvs/trunk/%f?view=log
Root.Html.Search:       http://www.google.com/search?q=%s+site%3A%u+-site%3A%u%2Fsrc%2F+-site%3A%u%2Fexamples%2F
#Root.Html.OutputDir:   htmldoc/
#Root.Html.Homepage:
#Root.Html.Header:
#Root.Html.Footer:
#Root.Html.Description: //____________________
#Root.Html.Author:      // Author:
#Root.Html.LastUpdate:  // @(#)
#Root.Html.Copyright:   * Copyright

# GUI specific settings.
Gui.Backend:                native
Gui.Factory:                native
# GUI style: modern (flat popup menus), modern-flat (flat frames), or classic (win 95 style)
Gui.Style:                  modern-flat
Gui.DefaultFont:            -*-helvetica-medium-r-*-*-22-*-*-*-*-*-iso8859-1
Gui.MenuFont:               -*-helvetica-medium-r-*-*-22-*-*-*-*-*-iso8859-1
Gui.MenuHiFont:             -*-helvetica-bold-r-*-*-22-*-*-*-*-*-iso8859-1
Gui.DocFixedFont:           -*-courier-medium-r-*-*-22-*-*-*-*-*-iso8859-1
Gui.DocPropFont:            -*-helvetica-medium-r-*-*-22-*-*-*-*-*-iso8859-1
Gui.IconFont:               -*-helvetica-medium-r-*-*-22-*-*-*-*-*-iso8859-1
Gui.StatusFont:             -*-helvetica-medium-r-*-*-22-*-*-*-*-*-iso8859-1
Gui.BackgroundColor:         #e8e8e8
Gui.ForegroundColor:         black
Gui.HighLightColor:          #d0d0d0
Gui.SelectBackgroundColor:   #d0d0d0
Gui.SelectForegroundColor:   black
Gui.DocumentBackgroundColor: white
Gui.DocumentForegroundColor: black
Gui.TooltipBackgroundColor:  LightYellow
Gui.TooltipForegroundColor:  black
#Unix.*.Gui.IconPath:         .:$(HOME)/icons:$(ROOTSYS)/icons:
#WinNT.*.Gui.IconPath:        .;$(HOME)/icons;$(ROOTSYS)/icons;
Gui.MimeTypeFile:            $(HOME)/.root.mimes
# If above does not exists defaults to this:
#Gui.MimeTypeFile:            $(ROOTSYS)/etc/root.mimes
# Type of Browser: TRootBrowser or TRootBrowserLite
Browser.Name:                TRootBrowser
# Browser Options (plugins)
# F: File browser E: Text Editor H: HTML browser
# C: Canvas I: I/O redirection P: Proof G: GL viewer
Browser.Options:             FCEI
# Can be either small, big, list, details
Browser.IconStyle:           big
# Can be either name, type, size, date
Browser.SortBy:              name
Browser.GroupView:           10000
Browser.ShowHidden:          no
Browser.AutoThumbnail:       yes
# Set the ExpandDirectories option to "no" to prevent expanding
...
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