1. Uninstalling the Uniblue product.
Bleeping Computer DOES NOT recommend the use of registry cleaners/optimizers for several reasons:
Registry cleaners are extremely powerful applications that can damage the registry by using aggressive cleaning routines and cause your computer to become unbootable.
The Windows registry is a central repository (database) for storing configuration data, user settings and machine-dependent settings, and options for the operating system. The registry is a crucial component because it is where Windows "remembers" all this information, how it works together, how Windows boots the system and what files it uses when it does. The registry is also a vulnerable subsystem, in that relatively small changes done incorrectly can render the system inoperable.
Not all registry cleaners are created equal. There are a number of them available but they do not all work entirely the same way. Each vendor uses different criteria as to what constitutes a "bad entry".
Not all registry cleaners create a backup of the registry before making changes. If the changes prevent the system from booting up, then there is no backup available to restore it in order to regain functionality. A backup of the registry is essential BEFORE making any changes to the registry.
The usefulness of cleaning the registry is highly overrated and can be dangerous. In most cases, using a cleaner to remove obsolete, invalid, and erroneous entries does not affect system performance but it can result in "unpredictable results". I think that you can see that now.
Why I dont use registry cleaners - http://www.edbott.com/weblog/?p=643
Should I Use A Registry Cleaner - http://aumha.net/viewtopic.php?t=28099 Unless you have a particular problem
that requires a registry edit to correct it, I would suggest you leave the registry alone.
I further susggest/emphasize that you back up the registry before attempting any manual edits of such in order to deal with known problems and remedies. An excellent toof for such backup is ERUNT Registry Backup Tool - http://www.snapfiles.com/get/erunt.html
2. Run either a repair install of XP...or run the sfc /scannow command to replace any missing/damaged system files.
How To Use Sfc.exe To Repair System Files - http://www.bleepingcomputer.com/forums/t/43051/how-to-use-sfcexe-to-repair-system-files/
How to Perform a Windows XP Repair Install - http://www.michaelstevenstech.com/XPrepairinstall.htm
3. Run the chkdsk /r command on the system partition.
4. Try the install.