The computer is very laggy and it takes a long time to open anything.

When your computer freezes or freezes, what are you doing on the computer? Can you tell me? I will answer you more accurately based on what you said.

Please describe in detail the performance of your computer before the screen freezes or crashes, and your operations. It may be these operations that caused the screen freezes or crashes. If you have any questions, please ask me (I will follow your instructions) The information provided will answer you again).

Generally, screen freezes or crashes are caused by incorrect operations. Remember not to perform operations that are likely to cause screen freezes or crashes. Do not operate the computer at full load. That is, when you are playing games, watching videos, downloading, or browsing web pages, it is most likely to restart, crash, or blue screen when doing other operations. Therefore, do not operate the computer while playing games, watching videos, downloading, or browsing web pages. Working on something else.

No matter what you are doing, as soon as there is any sign of lag, stop the operation at hand and exit the test. If it still happens, stop playing or watching.

In terms of hardware, if the memory module is small, add a memory module. If the temperature of the CPU and other hardware is too high or the hard disk has bad sectors, it may be caused by inappropriate hardware.

Win7 will be fine with 4G of memory. If it works better, add 4G of memory and change to a 64-bit system.