RC,

Perhaps.  It could also be a number of other things as well.   It is difficult to say what the root cause of that vague and common symptom is without checking out the PC but I'll give tell you what I think you should do and why.

First, it is a very common symptom of modern virus and spyware infections.  These days, viruses in many cases try not to raise as much attention to them selves.   They don't want to be removed.  Often your computer will be working very hard performing the virus's todo list and the appearance to you would simply be a slow-down or performance problem.  For the malicious programs that are designed to feed you advertisements, this is usually the case.  A virus scanning and cleaning will fix this problem should it be the case.  There is, however, a problem with this approach as I will describe.

Second, it is a very common symptom of a failing hard drive on the computer to suddenly slow down the computer as it tries to read and write to the disk over and over until it succeeds.  If you are lucky enough to get an early warning of this type of problem, this is often the warning.  This problem will eventually result in the loss of the information stored on your computer.  This can occur at any moment and could be days, hours,  or minutes away.

Conclusion: If you do not see any suspicious symptoms such as strange advertising and what appears to be hijacked search results from your Internet searches or pop up advertising and you didn't do anything different or install something from the Internet be cautious.  I recommend having your hard drive checked before you attempt to scan for viruses.  This should allow a technician to determine if your information is at risk of being lost.  The reason for this is that during the course of a virus scan, the intense work load of doing that can actually finish off a dying hard drive and leave you very disappointed if the information such as your pictures becomes lost.  This diagnosis can generally be made in our office in just a few minutes.

 MainSail Dale

RC,

Yes, we can test Hardrives to ensure they are running properly. Also, we will backup any information that is important to you before testing just to be safe.