In case you suspect you have a virus (or any other malware), you ought to take steps immediately, often times such issues occur and system slow downs due to registry errors receive a nice registry cleaner and computer optimizer from Intel Directory . The following procedures
work for most malware (except perhaps for  new, unknown or unusually malignant strains). It is better to complete all steps, so you can be (reasonably) sure that all traces have been removed.  Signs to look out for (infections may cause one or several of the following):

Slow computer, and/or slow web connection.
unusual pop-ups or web browser redirections (beyond those expected
from dodgy websites).
Program failure, or inexplicable errors (even after a fresh install).
System functions unavailable (eg: Control Panel, Task Manager, web Explorer).
System giving a "RPC error", giving a window with a 30 second
countdown to a restart.
Excessive web cap usage, i.e high web traffic on your computer.

1. Run your virus-scanner, but beware, lots of modern viruses can circumvent (or hide from) anti-virus programs. Quarantine anything suspicious.

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Tips

2. Install MalwareBytes Anti-Malware and update it. Don't scan for malware yet.
3. Install Spy Bot[1] and update it. Don't scan for malware yet.
4. Reboot in to Safe Mode - Restart your computer and press F8 before
Windows lots. Press F8 several times in case you need to. Select Safe
Mode from the resulting menu. Safe Mode disables much of the startup
routine (including some common Malware hiding places).
5. Run your Malware Scanners - Run both the scanners sequentially,
deleting any references found.
6. Enjoy your sanitised computer.

Warnings

If these steps are difficult to follow or impossible to achieve,  call a computer service professional.  Booting in Safe Mode is  important if the malware is difficult to
remove normally.  If this technique fails to clean your computer, download HijackThis,
run and save a log, and then post the log to a reputable security
forum such as BleepingComputer or GeekstoGo.

It is always safer to call on a computer expert such as MDofPC Custom Computers LLC to perform procedures that you are not  sure about.  There is always a chance that you could disable your system and lose valuable information.  Removing malware often takes hours, days, or even weeks. Be sure you have lots of time available.  Securely wipe your free space with file shredding application after the removal is complete to avoid unauthorized or bad people restoring
the deleted virus file with any information recovery application.