My computer is located near the window, and I noticed that when I open my window, after a minute or two the picture on the screen often gets blurry and I have to press "auto" to make it sharp again. Does temperature change somehow affect hardware parameters which causes the signal to change (and picture get blurry)?
The simple answer to your question is yes, excessive Temperature changes can effect visual output, however this typically relates to overheating and causes screen tearing, vertical scan lines, little speckles dancing around the screen, etc., but I have never seen this cause blurry images. It could be the monitor depending on age, but impossible to determine with limited info. If the computer is in a hot environment (85+ degrees) while a graphic intensive game is running, then the GPU could be exceeding its temperature threshold. Especially if the fan has not been cleaned in a while.
Some things I would try in order: - Get some compressed air, open case and clean all fans. (Power supply, CPU, GPU, etc.) - Check video cables when image becomes blurry. Does movement cause image fluctuation? - Test another monitor - Replace graphics card