Cleaning Windows regularly will help performance 

 do not place files on the desktop, rather create a DIRECTORY (Folder) and make a link to it.
 put files you work on in that created DIRECTORY - best NOT in your default "my Documents"
 you can copy the entire Directory to a Thumb drive easily
 create a batch file to execute the commands below - place this in the STARTUP FOLDER on your Windows machine
 do a disk cleanup at least once a week
 run defrag at least once a week - some versions do it automatically... check


NOTE:  change "LUSER" to your user name

 to clean your temp space without admin rights
cls
attrib -r -h -s -a c:\temp
del /S /Q C:\Temp\
del /S /Q C:\TEMP\*
del /S /Q C:\TEMP\
del /S /Q C:\Temp\*.*
del /S /Q "C:\Documents and Settings\LUSER\Local Settings\Temp\*.*"
del /S /Q "C:\Documents and Settings\LUSER\Local Settings\Temp\*"
del  /Q "C:\Documents and Settings\LUSER\Local Settings\Temporary Internet Files\*.gif"
del  /Q "C:\Documents and Settings\LUSER\Local Settings\Temporary Internet Files\*.jpg"
del  /Q "C:\Documents and Settings\LUSER\Local Settings\Temporary Internet Files\*.bmp"
del  /Q "C:\Documents and Settings\LUSER\Local Settings\Temporary Internet Files\*.gif"

echo Done!

 to clean all temp spaces, possibly without admin rights
cls

echo "cleaning windows temp"
attrib -r -h -s -a c:\windows\temp
del /S /Q C:\WINDOWS\Temp\
del /S /Q C:\WINDOWS\Temp\*
del /S /F /Q C:\WINDOWS\Temp\*.*
del /S /F /Q C:\WINDOWS\Temp\*.log
del /S /Q C:\WINDOWS\Temp\*.LOG
del /S /Q C:\WINDOWS\Temp\*.MTX
del /S /Q C:\WINDOWS\Temp\*.mts
del /S /F /Q C:\WINDOWS\Temp\*\*.*
del /S /Q C:\WINDOWS\Temp\*\*
del /S /Q C:\WINDOWS\Temp\*.cfg
del /S /Q C:\WINDOWS\Temp\*.dat
echo "cleaning temp"
attrib -r -h -s -a c:\temp
del /S /Q C:\TEMP\
del /S /Q C:\TEMP\hsperfdata_LUSER
del /S /Q /F C:\TEMP\pdfdownload
del /S /Q /F C:\TEMP\pdfdownload\*.*
del /S /Q /F C:\TEMP\*
del /S /Q /F C:\TEMP\VBE\*
del /S /Q /F C:\TEMP\VBE
del /S /Q /F C:\TEMP\Intuit\*
del /S /Q /F C:\TEMP\msohtml\*
del /S /Q /F C:\TEMP\msohtml
del /S /Q /F C:\TEMP\msohtml1\*
del /S /Q /F C:\TEMP\msohtml1
del /S /Q /F C:\TEMP\Intuit
del /S /Q /F C:\TEMP\Excel8.0
del /S /Q /F C:\TEMP\~nsu.tmp
del /S /Q /F C:\TEMP\svmb3.tmp
del /S /Q /F C:\TEMP\pdfdownload\*
del /S /Q /F C:\TEMP\*.*
del /S /F /Q C:\Temp\*.log
del /S /Q C:\Temp\*.LOG
del /S /Q C:\Temp\*.MTX
del /S /Q C:\Temp\*.mts
del /S /Q /F C:\Temp\*.tmp
del /S /F /Q C:\Temp\*\*.*
del /S /Q C:\Temp\*\*
del /S /Q C:\Temp\*.cfg
echo "cleaning local settings temp and internet cache"
del /S /Q "C:\Documents and Settings\LUSER\Local Settings\Temp\*"
del  /Q "C:\Documents and Settings\LUSER\Local Settings\Temporary Internet Files\*.gif"
del  /Q "C:\Documents and Settings\LUSER\Local Settings\Temporary Internet Files\*.jpg"
del  /Q "C:\Documents and Settings\LUSER\Local Settings\Temporary Internet Files\*.bmp"
date /t > lastclean.txt
echo Done!