Super Slow booting ever since Windows Security update

2-3 days ago, system asked me to install some security update, I said ok, it was 538 kb or something. Ever since this was done, system booting has become super slow. It takes almost 2-4 minutes for the lappy to boot earlier it took around 1-2 mins.

It goes on & on at first with the windows logo .. I begin to think may be system hanged then.. I get a black screen for a few secs.. then comes the "Please Wait" .. then, "Welcome" - it gets stuck with the welcome msg for a little while, again a black screen for 5-15 secs.. then I get into the desktop screen with the WP & etc...

This doesn't stop here, (I always have my desktop complete blank, I mean it - I prefer no icons in the desktop as I recall some one once saying having icons on desktop can slow up your system at start up especially. I don't have any icons in my desktop including Recycle Bin, I don't want them either). Earlier, when I used to get the desktop screen within a few secs Start Menu used to be ready displaying all the options but now all I see is a blank menu with only link to "All Programs".

I've already scanned system with Avira, Ad-Aware, there was one Trojan yesterday & it was removed as well. Still, I had super slow loading today as well.

I would really appreciate if I could improve my system's booting process, I don't want to loose my data with a fresh OS reinstall.

Try cleaning out all temp files. Please download TFC by Old Timer TFC - Temp File Cleaner by OldTimer - Geeks to Go Forums and save it to your desktop.
Save any unsaved work. TFC will close ALL open programs including your browser!
Double-click on TFC.exe to run it. If you are using Vista/Windows 7 right-click on the file and choose Run As Administrator.
Click the Start button to begin the cleaning process and let it run uninterrupted to completion.
Important! If TFC prompts you to reboot, please do so immediately. If not prompted, manually reboot the machine anyway to ensure a complete clean.

Uninstall Ad-Aware, then let's take a look at what might have come bundled with other downloaded programs.

Download DDS from one of these links:
DDS.com
DDS.pif

• Disable any script blocking protection
• Double click the dds icon to run the tool.
• When done, DDS will open two (2) logs:
  1. DDS.txt
  2. Attach.txt <--- will be minimized in the task tray
• Save both reports to your desktop.

Include the contents of both logs in your next post.
The scan will instruct you to post Attach.txt as an attachment.

Are you using a proxy? If you didn't set it, then disable the proxy settings in Internet Explorer:
1) Under “Tools” in the browser tool bar select “Internet Options”.
2) In the “Internet Options” window that pops up, click the “Connections” tab at the top.
3) Click “LAN Settings” near the bottom of the “Connections” section.
4) If the “Proxy server” checkbox is marked with a check, click it to deselect/uncheck it.
5) Click “Ok” to close the “Local Area Network (LAN) Settings” window.
6) Click “Ok” to close the “Internet Options” window.
Reboot
Make sure "Proxy server" is still disabled under your LAN Settings.

Next, let's use AdwCleaner to see if there might be some.... download AdwCleaner by Xplode and save to your Desktop.

• Double click on AdwCleaner.exe to run the tool.
  Vista/Windows 7/8 users right-click and select Run As Administrator.
• Click on the Scan button.
• AdwCleaner will begin...be patient as the scan may take some time to complete.
• After the scan has finished, click on the Report button...a logfile (AdwCleaner[R0].txt) will open in Notepad for review.
• The contents of the log file may be confusing. Unless you see a program name that you know should not be removed, don't worry about it. If you see an entry you want to keep, let me know about it.
• Copy and paste the contents of that logfile in your next reply.
• A copy of all logfiles are saved in the C:\AdwCleaner folder which was created when running the tool.

Using AdwCleaner v3: Scan & Clean:
Double click on AdwCleaner.exe to run the tool again.

• Click on the Scan button.
• AdwCleaner will begin to scan your computer like it did before.
• After the scan has finished...
• This time, click on the Clean button.
• Press OK when asked to close all programs and follow the onscreen prompts.
• Press OK again to allow AdwCleaner to restart the computer and complete the removal process.
• After rebooting, a logfile report (AdwCleaner[S0].txt) will open automatically.
• Copy and paste the contents of that logfile in your next reply.
• A copy of that logfile will also be saved in the C:\AdwCleaner folder.