Why does my computer become slower after switching from Win 7 32bit to Win 7 64bit?

Question

Iron

Development of events: Yesterday I bought 4GB of RAM and decided to reinstall Windows on 64bit, since RAM allows. So, already when installing Win, I noticed something was wrong, the windows (with a breakdown of disks / formatting, setting the time) that, during installation, climbed out instantly, now they crawled out after 20-30 seconds, well, I think okay, be patient and after completing the installation, I thought everything behind, but it wasn’t there ... After starting the computer, it turned on for 30-40 seconds longer than before, the installation of programs took much longer, while climbing on the computer and in the computer, I didn’t find anything, everything was as before, the only difference plus 4GB RAM and Windows 64bit. Even programs began to slow down somehow, CCleaner can stop during analysis and start checking 1 file for 5 seconds, how much I use it, this is the first time ...
Собственно вот конфигурация компьютера: Системная плата Gigabyte GA-880GA-UD3H v2 (3 PCI, 2 PCI-E x1, 2 PCI-E x16, 4 DDR3 DIMM, Audio, Video, Gigabit LAN, IEEE-1394), AMD Athlon II X2 250 Processor, NVIDIA GTS 450, 6,0GB RAM.
P.S Автозагрузки вроде пусты, но вот для знающих, на всякий случай.

Answer 1

The new memory may not be broken, but it differs in parameters from the existing one. This could theoretically work. Judging by the text, you added 4 more to 2GB. Try to leave only new memory in your computer (I hope you have it with one or the same modules).
Check the disk, maybe it got sick, and by coincidence it has now manifested itself?
Have all the drivers been installed under the new system, look in the manager - are there any unknown devices left?
Did you change BIOS settings? You can reset it to default just in case.

Answer 2

And before installation, we checked the memory with memtest eh?