System Restore points disappear after 1 day

Microsoft Windows XP

I recently noticed that my System Restore points are no longer available after 1 day. Yet, the RPLifeInterval is set to 90-day default. Is there another registry value that could cause this situation? I believe this problem began concurrently with a hijacking search page that I have apparently removed, but I still lose my restore points. Mucho thanks in advance.
First follow #1, #5 & #6 on this page to get rid of spyware and

Many things can cause loss of Restore Points, when they are gone, they
are gone and can not be recovered or used.
Some of the things are:
Available space on hard drive
Computer usage
Space you dedicate to System Restore

If you use Real Player, try doing without it for a few days:
And others.
Thanks, Jupie. It appears that it may be the RealOne Player connection.