When I googled msisvt32.dll I got "no results found". Whenever I see that I immediately start thinking virus or other malware. Legitimate .dll files almost always have information available about them. Suggest you run a full scan with your own updated antivirus suite. No anti-virus product is 100% effective 100% of the time (if there was such a thing we'd all be using it.) So I also recommend you scan your computer with some additional free on-demand scanners. The more scanners you use that come back "no malware found" the more likely your computer is not infected.
After running the malware scans I'd also check for damaged or corrupt system files. Run a system file checker scan from an elevated command prompt (option two.) If problems are found, run the scan 3 times and reboot the computer after each scan.
