DISK READ ERROR on BOOTUP

Hello,
I am using 2 OS, 1-Vista Ultimate, 2-XP professional in order basis to open bootup screen to choose which OS.
I have Intel DG35EC motherboard,
Intel Core2QUAD Processor-Q6600@2.4Ghz
2GB Kingston DDR2
250GB HDD SATA.
Today i cleaned my cpmputer table mostly because of DUST, so also little bit opened the cabinet with small brush cleaned some dust inside CPU, not unplugged the connections of all the devices.
Then when i put the pwer wire for UPS then switchng the Cabinet]CPU] Power ON, an INTEL screen displays to coose BIOS setting F2, so i restarted so many time, same INTEL display came, so i tried to pressed F2, nothing happens.
So i switched off the CPU[cabinet Power ON/OFF], totally switched off all the UPS connections from the wall mount pwer also. so i opened the cabinet box, lightly touched the wires mostly SMPS to motherboard, to check the wire properly connected not loosely, also checked the other wires lightly touched to check whether the wires connected loosely or not.[not unplugged all the wires].
Then i tried to put the wall mount power ON to UPS, switched the UPS ON, then switched ON the CPU, then the display came like,
DISK READ ERROR, try to press ALT+CTRL+DELETE to restart.
so i restarted, nothing happens to boot, so i gain off all the units, to check the wires, then switched ON all the units,
Then lately came Dual OS options very lately, tried to open Vista OS, by long times it didn't opened the OS, just Like Processing windows bar screen like opening, it takes ling time showing like this, so i restarted to switched to SAFE mODE, opened normally, restarted again by normal windows Vista OS, same thing so it takes long time. so i frustrated t try to open windows XP OS,
It also take some time to open XP OS, then after some minutes, it openes, not like like normal speed, takes some time slowly to open OS.
Now i am trying this internet to search for help to ask from u all.

WHAT Happened to my PC, isn't i touched the wires for slight bit cleaning dusts, so might it takes some errors to my Hard disk to open and showing this error message on Bootup.

Please help me how to resolve this and to open my Vista Ultimate and also XP normal conditions.

Please help me......