Question : Computer reboots on Recovery console

I have a Dell Dimension 3000.   It has been shutting down at intermitent times and running real slow.   I found that one stick of RAM was bad.  I have run through anti-virus and anti-malware.   I have run UBCD tests on hard drive, CPU and memory and they all pass.  The issue now is when I try to go into recovery console to run chkdsk /r it reboots before I can type in chkdsk /r.   SO I tried to run repair on windows with XP CD.  It keeps getting stuck on 39 minutes left with "Cyclical redundancy check".   I know the cd is a microsoft original copy in good condition.   What is doing this?   DOes this mean I need to wipe hard drive and re-install everything?

Answer : Computer reboots on Recovery console

The problem is quite possibly a damaged or dirty CD.  (Yep, I know you said it is a microsoft orignal copy.  Is this a copy or an original CD?  If this is a copy then quite likely the copy isn't good).

Or possibly a failing CD drive.  But I prefer the damaged or dirty CD.