Question Installed RAM and now bluescreens. What Do?

[S_Bard]

A month and 5 days ago i installed some ram (4gb Kingston kvr13n9s8) that seemed compatible with the 4 gigs of ram that i had (4gb Kingston KVR1333D3N9/4G). It worked fine, until it didn't. My computer started crashing and bluescrening and taking forever to start up, starting from occasionally and ending in me not being able to use the pc for more than 15m.
I didn't know what to do so i decided to format the computer, did that, bluescreened, installed all the drivers i needed and then everything worked fine for about a week. Now it bluescreened again, and wasn't starting up, so i removed the new RAM and it started up fine.

TL;DR Installed 4gb of RAM worked for a month and then bluescreens.
What can i do, did i buy the wrong RAM? Is it a problem with the BIOS? Is it a problem with other hardware?

Stuff:
Mother: GA-H61M-DS2 (rev.2.2)
CPU: Intel Core i3 2120 (Sandy Bridge)
PSU: Generic 300W (the fan broke years ago but it still hasn't catched on fire)
RAM: Kingston KVR1333D3N9/4G (current) Kingston kvr13n9s8 (the one that i just removed)
Storage: I actually don't have a clue what i have, never removed it from the pc since the cables (i think they are sata?) are Removed glued to the hard drive, and the case is micro atx so you know.

 

[Deleted member 14196]

Mixing the ram was your first big mistake. Go buy a proper kit of matched ram sticks that are compatible

 

[S_Bard]

I checked and they seemed compatible, they shared the same speeds, size, types, brand. The only diference was a slightly different model

 

[lynx1021]

They have to be declared compatible by the Vendor, there are a lot of memory specs that the memory vendors keep secret.
According to Kingston KVR1333D3N9/4G is compatible with your board, kvr13n9s8 is not. The KVR1333D3N9/4G is low density 16 chip per module where kvr13n9s8 is high density 8 chip per module. You would have better luck buying another KVR1333D3N9/4G module on eBay or amazon.

 

[lynx1021]

Or you can get a matched Pair of 8GB sticks for a 16GB kit here https://www.crucial.com/usa/en/ga-h61m-ds2-r2/CT13534081