In a system that works, things like that shouldn't happen, and an NSIS installer cannot do this even if it wanted to. This is a symptom, not the issue.
You should check your computer for
- intrusive AV software (some consider this malware too)
- faulty RAM
- faulty HDD (or faulty file system)
- overheating (mostly CPU)
CPU: AMD Phenom II X4 810 @ 3250MHz | RAM: Kingmax 2x2GB DDR2 800 @ 833MHz| MoBo: MSI K9A2 CF v1.0 (BIOS: 1.D)| GPU: Asus HD 6850 1024MB (DirectCu) @ 850/1150MHz | Display: L24FHD | PSU: PC Power & Cooling Silencer 750 Quad | OS: MS Windows 7 Pro x64
CPU: Pentium 4 Northwood S478 @ 3200MHz | RAM: 1,5GB DDR 400| MoBo: Gigabyte GA-8S661FXMP-RZ | GPU: ASUS Radeon X1650 Pro 256MB | Display: Dimarson 19" CRT | PSU: Noname 400W | OS: changing twice every week...