i have tried Ccleaner and a few other free downloads and once they run the scan they say I need to buy the real version because I have to many files found to be cleaned up. I need to make sure I don't get rid of anything important that is installed on my computer.

I've been getting a blue screen with the following message: Run a system diagnostic utility supplied by your

Try changing video adapters. Disable and remove any newly installed hardware and drivers.
Disable and remove any newly installed software.

What does all this mean?

My computer has been very slow lately and I ran disk clean up and did defragmentation yesterday. However, I'm still getting blue screens.

How can I fix my computer? Would you please describe step by step the whole process.
Thanks.

P.S. I have a Dell computer, a windows xp

i have recently recovered from a virus attack on my pc, and i now have some missing files that were most likely deleted during cleanup.

i don't want to lose all the software and data that i have accrued since i got the computer.

Not only that, I need Virus Protection, anti spy, and firewall. I've been using the suite that is included with ATT Yahoo DSL but I need a different one because I purchased a new computer with Vista and they dont support Vista (and won't until at least August). Preinstalled on my computer I have a free trial of Norton but I was not happy with them on my last computer because I felt they take up too much memory. Give me some suggestions and why. I need the works but they don't have to be from the same provider. I was leaning toward computer associates but tell me what you think.

I keep getting pop ups that is telling me it is corrupted.