If it is only your mobile being near your PC that causes it to crash then move it away. If it is the mobile generating a signal in a landline that is near the PC then move the mobile from the landline and check/replace your filter(s). Any signal to a mobile will generate an electronic signal which may easily cause interference in components in the PC unless it is hardened (shielded) from them. Hardening a PC may not be easy, cheap or practical and as a result distance from the cause of the problem (crashing) is the simplest and most practical solution.
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