I have an HP DV Laptop. A couple of months ago, it suddenly took a long time to boot up (varies from approximately 40 minutes to 70 minutes). Even when it eventually boots up, it freezes approximately every one minute (but only for about 5 seconds). It's at its worst right after it finally boots up, and seems to get somewhat better after its been on (and used) for several hours. I have run all kinds of anti-virus programs with no success. Any suggestions?