Welcome Screen Delay

I installed and activated my Windows 7 Ultimate x64 on my Laptop PC. The official release. When I installed it worked perfectly, Boot Time Duration was about 35 - 45 seconds (measured with Event Viewer). Then I installed drivers for my PC. After installing drivers, I noticed that startup was much slower and after reinstalling system and drivers about 10 times and some searching on the web, I found out that the problem was my graphics card driver, which had built in Catalyst Control Center, software which was developed for editing graphics card settings, which I don't need (I am sure Catalyst Control Center caused delay because other drivers didn't affect welcome screen display time and boot time - after I installed them, Boot Time Duration was almost the same). So I installed system and drivers eleventh time in a row without Catalyst Control Center and it worked fine. Boot Time was about 50 - 60 seconds and I was very satisfated. After that I had some problems configuring Windows Update, so i had to reinstall system and drivers again. I did it, and welcome screen delay happened again. I have to wait 20-30 seconds watching 'Welcome Screen' before displaying desktop every time I turn on my PC. Boot Time Duration is sometimes over 120 seconds.

Before every installation, I formatted my 150 GB (C:) hard drive (I don't know whether formatting hard drive can affect boot time). As I stated, hard drive was formatted more than 10 times. I used Disk Defragmenter and fragmented % of Partition was 4 %. After defragmentation, it's again 0 %.

During last windows 7 installation, I deleted all my Hard Drives, made a new one and formated it (465 GB). After installing windows on this Hard Drive, another one problem happened. Another one delay. Before displaying Welcome Screen, screen on laptop goes blank for 5-10 seconds. I reinstalled system and drivers again and nothing changed. (I used Disk Defragmenter again; fragmented % was 3 %, now it's 0%.)

I tried this for fixing the problem:

1. Repaired startup using installation disc for Windows 7
2. Tried Microsoft hotfixes for this problem, including this one: The Welcome screen may be displayed for 30 seconds during the logon process after you set a solid color as the desktop background in Windows 7 or in Windows Server 2008 R2
3. Turned off all unneeded startup items in 'msconfig' (only things still running are: avast! Antivirus, Synaptics Pointing Device Driver & Intel USB 3.0 Monitor - they didn't cause delay, because after turning them off delay still was there).
4. Used: Disk Defregmenter, Disk Cleanup, System File Checker (System File Checker didn't find any problems).

Here is my PC Configuration:

Laptop PC: Toshiba Satellite C855-12K (PSKCEE)
System Version: 6.1.7601 Service Pack 1 Build 7601
Processor: Intel(R) Pentium(R) CPU B960 @ 2.20GHz, 2200 Mhz, 2 Core(s), 2 Logical Processor(s)
RAM: 4 GB
Graphics Card: AMD Radeon HD 7610M

PS: Sorry for too long description. Please help and ask for more info if you need. I hope this problem will be solved, thanks in advance.

SOLVED!

Finally! Suprisingly, the key thing was: DISK DEFRAGMENTER.

As said above, I have already tried Disk Defragmenter and it didn't seem helpful. But when I ran it last time, it behaved in a different way. When I tried it for the first time, I analyzed my Local Disk (C:) (button 'Analyze'), fragmented % was 4 %. After that, I pressed 'Defragment'. Disk Defragmenter did this:
1. analyzing;
2. defragmentation;
3. consolidation.
Complete process finished with Pass 3.

The last time I ran it, it was different. It did this:
1. analyzing;
2. defragmentation;
3. relocation;
4. consolidation.
Complete process finished with Pass 9. It also took much more time to complete.

From my experience there are some thing that I (don't) suggest.
1. Startup Repair from system installation disk. In my case, it wasn't helpful, it even worsened Boot Time. After I had ran it, another bad thing happened: after 'Welcome Screen', there was a little black screen delay, before the appearance of the desktop.
2. Important and helpful thing was Disk Cleanup. After I had ran it, I noticed slight improvement, not only in Boot Time, but in overall performance.
3. Be careful when you install Drivers. When I bought my laptop, there were too many unneeded drivers. They take a lot of RAM, slowing down startup time and overall performance.