That's not exactly a lot of information to isolate an issue. Here's some steps I would take if it is indeed a software issue:
- Run the computer in safe mode. See if the problem persists by trying to recreate the cpu spike within safe mode. Chances are that if the CPU does spike while in safe mode that you have a hardware problem. If it does not spike, it is most likely a virus or software issue.
For software issues:
- Get an antivirus scanner such as MalwareBytes. Run the full system scan and remove anything unwanted.
- Use the hotkey WIN+R to open the run dialog. Type "msconfig" without quotes in the text box and then click OK on the dialog. First, click the "startup" tab and disable any programs which you do not need to run on Windows startup. (Be careful not to disable anything important... Google any items if you are unsure if it should be disabled). Then click the "services" tab and check "Hide all Microsoft Services" at the bottom of the window. Proceed to disable any unneeded startup services just like you have done on the "startup" tab. Click Apply and then OK on the window. (It may prompt you to restart your machine).
- Once again, use WIN+R to open the run dialog. Open "regedit" with administrative access. Browse to these locations within RegEdit and tell me if you see any keys other than the default standard ones:
HKEY_CURRENT_USER\Software\Microsoft\Windows\Curre ntVersion\Run
HKEY_CURRENT_USER\Software\Microsoft\Windows\Curre ntVersion\RunOnce
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Run
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\RunOnce