programs just don't load

Hi! please help me with this one:
I have win7 rtm installed for 2 months now and all worked great.
Today, when i started the pc, all programs that were loading at startup started correctly, but everything else just does not load. any program i click appears in task manager with just a few kb of memory allocated and just hangs there without loading. I haven't made any changes recently and I didn't install other programs during last week. I have Kaspersky internet securty 9 no viruses detected. Strangely everything works fine when i boot-up in "debugging mode" from boot menu.
btw, what is actually "debugging mode"? and please don't tell me "Starts Windows 7 in an advanced troubleshooting mode intended for IT professionals and system administrators." because that does not actually explain anything.
Any help appreciated ! thanks

later edit: i forgot to mention that before this happened, i shut down windows because Eclipse was not working(it was using 100% cpu every time i tried to write something or open/close a java file). Than i put a fresh copy of Eclipse but the problem persisted, so i restarted the PC. After that the problem occurred...

Welcome to SF!

Have you tried running a virus scan? Download Malwarebytes free and scan.

~Jonathan

Please run Malwarebytes. It is reputed for being good at picking up virus that no other A/V can.

After you do that, try a System Restore if it still does not work.

~Jonathan

i don't have a restore point. I don't know why. Actually I used the restore point i had about 2 weeks ago
thanks, i didn't search for spyware, i will try that

later edit: i forgot to mention that before this happened, i shut down windows because Eclipse was not working(it was using 100% cpu every time i tried to write something or open/close a java file). Then i put a fresh copy of Eclipse but the problem persisted, so i restarted the PC. After that the problem occurred...

even later edit: Malwarebytes(full scan) did not find any infections or spyware/malware programs, but thanks for the advice.
Any other ideas?

Try disabling all non-Microsoft services on startup in msconfig.