You may also want to check what Microsoft says about its Security Update.
http://www.microsoft.com/technet/security/Bulletin/MS05-020.mspx
If you dig down through "Security Update Information", they finally tell you
what files on which they they did things - with time stamp and size. I found
this thru an explanation by PA_Bear (Thanks PA_Bear!) - otherwise I was just
as concerned about this as you.
Table
"The English version of this security update has the file attributes that
are listed in the following table. The dates and times for these files are
listed in coordinated universal time (UTC). When you view the file
information, it is converted to local time. To find the difference between
UTC and local time, use the Time Zone tab in the Date and Time tool in
Control Panel.
Internet Explorer 6 for Windows XP Service Pack 2:
File Name Version Date Time Size Folder
Browseui.dll
6.0.2900.2627
10-Mar-2005
08:02
1,016,832
SP2GDR
Cdfview.dll
6.0.2900.2627
10-Mar-2005
08:02
151,040
SP2GDR
Iepeers.dll
6.0.2900.2627
10-Mar-2005
08:02
250,880
SP2GDR
Inseng.dll
6.0.2900.2627
10-Mar-2005
08:02
96,256
SP2GDR
Mshtml.dll
6.0.2900.2627
10-Mar-2005
08:02
3,010,560
SP2GDR
Msrating.dll
6.0.2900.2627
10-Mar-2005
08:02
146,432
SP2GDR
Shdocvw.dll
6.0.2900.2627
10-Mar-2005
08:02
1,483,264
SP2GDR
Shlwapi.dll
6.0.2900.2627
10-Mar-2005
08:02
473,600
SP2GDR
Urlmon.dll
6.0.2900.2627
10-Mar-2005
08:02
607,744
SP2GDR
Wininet.dll
6.0.2900.2627
10-Mar-2005
08:02
656,896
SP2GDR
Browseui.dll
6.0.2900.2627
10-Mar-2005
07:43
1,016,832
SP2QFE
Cdfview.dll
6.0.2900.2627
10-Mar-2005
07:43
151,040
SP2QFE
Iepeers.dll
6.0.2900.2627
10-Mar-2005
07:43
250,880
SP2QFE
Inseng.dll
6.0.2900.2627
10-Mar-2005
07:43
96,256
SP2QFE
Mshtml.dll
6.0.2900.2627
10-Mar-2005
07:43
3,011,072
SP2QFE
Msrating.dll
6.0.2900.2627
10-Mar-2005
07:43
146,432
SP2QFE
Shdocvw.dll
6.0.2900.2627
10-Mar-2005
07:43
1,484,288
SP2QFE
Shlwapi.dll
6.0.2900.2627
10-Mar-2005
07:43
473,600
SP2QFE
Urlmon.dll
6.0.2900.2627
10-Mar-2005
07:43
607,744
SP2QFE
Wininet.dll
6.0.2900.2627
10-Mar-2005
07:43
657,920
SP2QFE
Note When you install this security update on Windows XP Service Pack 2, the
installer checks to see if one or more of the files that are being updated
on your system have previously been updated by a Microsoft hotfix.
If you have previously installed a hotfix to update an affected file, the
installer copies the SP2QFE files to your system.
If you have not previously installed a hotfix to update an affected file,
the installer copies the SP2GDR files to your system.
For more information about this behavior, see Microsoft Knowledge Base
Article 824994.