Hi
This has been a pain in the proverbial since Microsoft released Windows Vista and Windows 7. It is to do with the number of "svchost" tasks that are running in the background and eating up system resources which is why it affects multiple applications. I am not a techy but I understand there is little that can be done about it, unless you are running a PC with little RAM, it may improve if you increase the RAM.
Unfortuhnately all you can do is let the PC finish running the background svchost tasks and it will return the system to you.
Sorry I could not be of more help.
Tony(OTPM)