Windows 7 - problem with windows 7 64bit

hi
first i apologize for the bad English.

I had windows 7 32bit till it crashed when I was removing win32 virus in system32 folder.
So I had to install windows again because it was stopping on starting windows logo and didn’t start even in safe mode.
I installed windows 7 64 bit .
My drive c was fully reinstalled again but I recover my drive d with my personal information.
Now the windows works slowly and sometimes hangs up for a few seconds.
After 2 days when I was watching a video file suddenly the windows crashed again:
System check started to work .
Windows hid All my drive d and library.
I had an error message
unfortunately I do not recall the error message .(something about low memory or speeding down)
So I had to use a restore point from 2 days ago from safe mode.
Its ok now.
But I was wondering that you can help me figure out what was the problem.
Is it because I installed 64 bit and I recover my datas?
Or its something else(like a program that suit 32 bit,windows update)?
can i make my windows works faster?

Thanks for your help

Here is my system information:

Have you installed all the device drivers for your hardware? I'd recommend the ones from the manufacturer, and not relying on the ones built into Windows. Windows 7 does a great job of identifying your hardware and getting you up and running quickly, but when it comes to performance the manufacturers driver almost always is better.

You might also want to fill in your specs under "My System Specs in your SevenForums Control Panel.

Your English is pretty good, by the way.

Is that windows 7 legit? If not, try a clean unmodified/patched version.

Work through these troubleshooting steps after running a full scan with Malwarebytes.

thanks i will try
see if they work