Like many, I have a laptop running Windows 7 + background MSE Virus detection software. Two very good products that are made to "inter-connect" with one another, and both download free Updates / Patches as well. And like many, I set my computer to perform Full Scan every other night. Since my kids, my boss (that's my wife LOL!) and I use this laptop from taxes, to school work, to recording music, to playing movies, I keep its Wireless, Firewall and other security settings "very tight".
For the last 7-9 days, I noticed my laptop getting more and more sluggish. And, I notice its cooling fans spinning faster and faster as well. Like its being "over worked" too much. And, I notice its download speeds taking longer and longer each day as well. Since 8:00 PM (for the last 4 hours), I've been investigating the situation. Finally, I found the problem. An undetected Virus / Trojan on its hard disk. It was a slippery one but I found it. And, nailed it back!!!
If wondering, I erased its many files, disabled its auto-load Service and locked down its firewall even tighter. Took me some time to "force stop" its auto load file (so it can be deleted) but, I finally got it. That file is now trashed and counter blocked. As they say at a chess game, "Check and Check Mate". Or what some might say, "a splattered bug under the hard bottom shoe". Ouch!!!!
If your MS Windows 7 is bogging down and you suspect its a background virus, do search its hard disk for a file called "RLVKNLG.EXE". If you have this file on your hard disk, its file and its Service (which auto-loads at Startup) must be manually removed from your system.
Now..... I cannot believe how fast my laptop is. Its super fast. Especially after I disabled some of its HP "bloat ware" as well. But, that's a topic for a different post...