I have an Acer Aspire am1640-e1510B, and a while ago I added an nVidia GeForce 9500GT, no problems there. I then added 4 gb of Adata DDR2 800 ram in two 2gb sticks, and since then when playing a game such as Fallout: New Vegas or League of Legends, the display will get fuzzy or totally go berserk sometimes, but more often will freeze for 1-2 seconds, flash black and continue working. Twice now, I got a BSoD while playing New Vegas that mentioned the display drivers, but those are up to date. I am using Windows Vista.
I suspect power supply issues or temperature issues, but Everest says my computer is about 45 degrees Celsius. I am totally new at this, and would appreciate some advice. If this belongs in a different category, please let me know.
More about :9500gt working sporadically installing ram
Are you running 32-bit or 64-bit Vista? If 64-bit, is it seeing all 4 GB of RAM? If not, then chances are, you are running into a motherboard chipset limitation which caps you at something south of 4 GB of RAM despite having a 64-bit operating system. In addition, some of these chipsets get really flaky when using 4 GB of RAM and a PCI-Express video card.
So that might be what you're running into.
See if the BIOS has a "Memory remapping" or "Memory hole" option so that the address space for hardware (like your card) gets mapped above the 4 GB ceiling. If not, then you may just be stuck at 4 GB of RAM without a PCI-e card or 2-3 GB of RAM with one.
I am running the 32-bit version of Vista, and it sees 3070 MB in Task Manager. I will run Memtest and return with results.
EDIT: Memtest says it is fine.
EDIT2: I replaced two 1gb DDR2 800 sticks by Transcend. They came with the computer.
EDIT3: On the side on my PSU, it says FSP Group Inc., and the model number is ATX-250PA (1). It has a line labeled AC Input, which reads: 100-127/220-240V-, 6/3. 15A, 60/50Hz, and DC Output says: 250W (+3.3V & +5V=110W Max) (+12V1 & +12V2=180W Max)