I have an old but lightly used Dell Inspiron 9200 running a Pentium M, 755 Processor. A couple of months ago I fired it up after it had been sitting idle for almost is or a year. I noticed that it was running unusually slow. After a couple of days of running diagnostics I found that the processor is only running at about one fourth of its rated speed. I have tried disabling speed step, reinstalling the OS, and drivers and updating any dated drivers that I could. It is still running at 598 Mhz instead of 2.0 Ghz. Is there any way to fix this or do I just use it as a paperweight?
I am having the exact same problem as you. I tried reinstalling and same result. If you have any luck with it let me know and ill do the same.